Cap Liners, Closures, and Gaskets from Multi-Block Polymers

ABSTRACT

A polymer composition comprises at least an ethylene/α-oleiln interpolymer and at least one other polymer. The other polymer can be selected from a second ethylene/α-olefin interpolymer, an elastomer, a polyolefin, a polar polymer, and an ethylene/carboxylic acid interpolymer or ionomer thereof. The ethylene/α-olefin interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comonomers than the hard block. The block interpolymer has a number of unique characteristics disclosed here. Also provided are gaskets, bottle cap liners, and closures that comprise or obtained from a compositon comprising at least one ethylene/α-olefin interpolymer and at least one polyolefin. The gaskets are capable of compression sealing various containers, without contaminating the contents. Liquid containers particularly benefit from the use of the novel gasket materials disclosed herein.

FIELD OF THE INVENTION

The invention relates to polymer blend compositions comprising at leastone ethylene/α-olefin polymer and a second polymer which is differentfrom the ethylene/α-olefin polymer. In particular, this inventionrelates to gaskets, cork closures, and bottle cap liners comprising orobtainable from the blend compositions.

BACKGROUND OF THE INVENTION

Gaskets have been made from a variety of structural materials, includingpolymers such as ethylene/vinyl acetate (EVA) and polyvinyl chloride(PVC). For example, U.S. Pat. No. 4,984,703 discloses plastic closureswhich have a sealing liner comprising a blend of ethylene/vinyl acetateand a thermoplastic elastomeric composition.

Depending on the use environment, gaskets can have varying degrees ofproperties. For example, in corrosive service conditions, the gasketshould be impervious to the material in question, but still resilientenough to form a seal. Gaskets used in the food and beverage area havesimilar requirements, but cannot contaminate the foodstuff. For example,when a gasket is used as a bottle cap closure liner and the closure isapplied and removed (and/or resealed), it is desirable for the gasket toretain its integrity and not shred or tear (known in the industry as“stringing” or “scuffing”) such that pieces of it contaminate thefoodstuff. Further, the gasket or closure liner should not deform suchthat it loses its seal integrity. Depending upon the type of food and/orliquid contents, the filling temperature might be lower or higher thanroom temperature, thus placing even greater demands on the gasket.

While there have been many different gasket materials, there continuesto exist a need for olefin polymers and olefin polymer compositionsuseful in making gasket materials, and in the case of foodstuff, withoutadversely contributing to the taste and/or odor of the product.

SUMMARY OF THE INVENTION

The aforementioned needs are met by various embodiments of theinvention. In some embodiments, the polymer blend compositionscomprises:

-   -   (A) at least one ethylene/α-olefin interpolymer and (B) at least        one other polymer which is a different component than the        ethylene/α-olefin interpolymer, wherein the ethylene/α-olefin        interpolymer:        -   (a) has a M_(w)/M_(n) from about 1.7 to about 3.5, at least            one melting point, T_(m), in degrees Celsius, and a density,            d, in grams/cubic centimeter, wherein the numerical values            of T_(m) and d correspond to the relationship:

T _(m)>−2002.9+4538.5(d)−2422.2(d)², or

-   -   -   (b) has a M_(w)/M_(n) from about 1.7 to about 3.5, and is            characterized by a heat of fusion, ΔH in J/g, and a delta            quantity, ΔT, in degrees Celsius, defined as the temperature            difference between the tallest DSC peak and the tallest            CRYSTAF peak, wherein the numerical values of ΔT and ΔH have            the following relationships:

ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,

ΔT≧48° C. for ΔH greater than 130 J/g,

wherein the CRYSTAF peak is determined using at least 5 percent of thecumulative polymer, and if less than 5 percent of the polymer has anidentifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.; or

-   -   -   (c) is characterized by an elastic recovery, Re, in percent            at 300 percent strain and 1 cycle measured with a            compression-molded film of the ethylene/α-olefin            interpolymer, and has a density, d, in grams/cubic            centimeter, wherein the numerical values of Re and d satisfy            the following relationship when ethylene/α-olefin            interpolymer is substantially free of a cross-linked phase:

Re>1481−1629(d); or

-   -   -   (d) has a molecular fraction which elutes between 40° C. and            130° C. when fractionated using TREF, characterized in that            the fraction has a molar comonomer content of at least 5            percent higher than that of a comparable random ethylene            interpolymer fraction eluting between the same temperatures,            wherein said comparable random ethylene interpolymer has the            same comonomer(s) and has a melt index, density, and molar            comonomer content (based on the whole polymer) within 10            percent of that of the ethylene/α-olefin interpolymer; or        -   (e) has a storage modulus at 25° C., G′(25° C.), and a            storage modulus at 100° C., G′(100° C.), wherein the ratio            of G′(25° C.) to G′(100° C.) is in the range of about 1:1 to            about 9:1; or        -   (f) at least one molecular fraction which elutes between            40° C. and 130° C. when fractionated using TREF,            characterized in that the fraction has a block index of at            least 0.5 and up to about 1 and a molecular weight            distribution, Mw/Mn, greater than about 1.3; or        -   (g) an average block index greater than zero and up to about            1.0 and a molecular weight distribution, Mw/Mn, greater than            about 1.3.

In the polymer compositions, the other polymer is selected from a secondethylene/α-olefin interpolymer, an elastomer, a polyolefin, a polarpolymer, and an ethylene/carboxylic acid interpolymer or ionomerthereof. When the other polymer is a second ethylene/α-olefininterpolymer, the two ethylene/α-olefin interpolymers in the polymerblend compositions are different in comonomer content, molecular weight,structure, etc. Moreover, the two ethylene/α-olefin interpolymers candiffer in melt index and/or overall density.

In some embodiments, the first ethylene/α-olefin interpolymer in thepolymer blend compositions is present in an amount ranging from about 1%to about 99.5%, 5% to about 99.5%, 9% to 99.5%, 20% to about 80% or 10%to about 70% and the other polymer is present in an amount ranging fromabout 1% to about 99.5%, 5% to about 99.5%, 9% to 99.5%, 20% to about80% or 10% to about 70% by total weight of the composition.

The ethylene/α-olefin interpolymers used in the polymer blendcompositions have the processability similar to highly branched lowdensity polyethylene (LDPE), but the strength and toughness of linearlow density polyethylene (LLDPE). However, the ethylene/α-olefinpolymers are distinctly different from traditional Ziegler polymerizedheterogeneous polymers (e.g., LLDPE) and are also different fromtraditional free radical/high pressure polymerized highly branched LDPE,and different from metallocene or single site catalyzed polymers. Thisdifference is believed to arise from the blocked nature of theinterpolymer backbone. That is, nearly every interpolymer molecule has asegment of essentially linear monomer (e.g., high density polyethylenehaving little or no short chain branching from comonomer incorporation)alternating with a segment of highly short chain branchedethylene/α-olefin (e.g., from higher incorporation of α-olefincomonomer). This blocked nature of the backbone leads the interpolymersto have surprising performance, especially with regard to hightemperature performance for such beneficial properties such as abrasionresistance, and the interpolymers have a melting points higher than thatof traditional polyethylene, and random interpolymers ofethylene/α-olefins at the same or similar densities. For example,blocked interpolymers useful in embodiments of the invention having anoverall density of about 0.9 g/cm³ have a melting point of about 120°C., whereas a Ziegler-Natta polymerized ethylene polymer (traditionallylabeled LLDPE) having about the same density have a melting point ofabout 122° C., and a random ethylene/alpha-olefin interpolymer (such asthat made using metallocene or single site catalysis) having about thesame density have a melting point of about 90° C.

In some embodiments, the other polymer is an elastomer selected from athermoplastic vulcanizate, block copolymer, neoprene, functionalizedelastomers, polybutadiene rubber, butyl rubber or a combination thereof.In some embodiments, the other polymer is a polyolefin selected fromLDPE, LLDPE, HDPE, EVA, EAA, EMA, ionomers thereof, metallocene LLDPE,impact grade propylene polymers, random grade propylene polymers,polypropylene and a compbination thereof. In some embodiments, the otherpolymer is a polar polymer selected from nylon, polyamide, ethylenevinyl acetate, polyvinyl chloride, acrylonitrile/butadiene/styrene (ABS)copolymers, aromatic polycarbonates, ethylene/carboxylic acidcopolymers, acrylics and a combination thereof. In other embodiments,the other polymer is a olefin/carboxylic acid interpolymer selected fromethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers,ethylene-itaconic acid copolymers, ethylene-methyl hydrogen maleatecopolymers, ethylene-maleic acid copolymers, ethylene-acrylic acidcopolymers, ethylene-methacrylate copolymers, ethylene-methacrylicacid-ethacrylate copolymers, ethylene-itaconic acid-methacrylatecopolymers, ethylene-itaconic acid-methacrylate copolymers,ethylene-methyl hydrogen maleate-ethyl acrylate copolymers,ethylene-methacrylic acid-vinyl acetate copolymers, ethylene-acrylicacid copolymers, ethylene-acrylic acid-vinyl alcohol copolymers,ethylene-acrylic acid-carbon monoxide copolymers,ethylene-propylene-acrylic acid copolymers, ethylene-methacrylicacid-acrylonitrile copolymers, ethylene-fumaric acid-vinyl methyl ethercopolymers, ethylene-vinyl chloride-acrylic acid copolymers,ethylene-vinylidene chloride-acrylic acid copolymers,ethylene-vinylidene chloride-acrylic acid copolymers, ethylene-vinylfluoride-methacrylic acid copolymers,ethylene-chlorotrifluoroethlyene-methacrylic acid copolymers and acombination thereof.

The polymer composition may further comprise an additive selected from aslip agent, anti-blocking agent, plasticizer, antioxidant, UVstabilizer, colorant, pigment, filler, lubricant, antifogging agent,flow aid, coupling agent, cross-linking agent, nucleating agent,surfactant, solvent, flame retardant, antistatic agent, oil extender,odor absorber, barrier resin. The slip agent may be selected frompolymethylsiloxane, erucamide, oleamide and a combination thereof. Theextender may be a mineral oil, polybutene, siloxane, or a combinationthereof. The odor absorber can be calcium carbonate, activated charcoalor a combination thereof. The barrier resin used herein can be selectedfrom EVOH, PVDC and a combination thereof.

Also provided are articles comprising the polymer compostions. Oneexemplary artcle is a gasket comprising the composition provided herein.The ethylene/α-olefin interpolymers in the compositions have an unusualcombination of properties, making them especially useful for gasketmaterials comprising the compositions. Preferably, the ethylene/α-olefininterpolymer is an ethylene/C₃-C₂₀ alpha-olefin interpolymer. In someembodiments, the other polymer in the gasket comprises theethylene/carboxylic acid interpolymer or ionomer thereof in an amountfrom about 4 percent to about 12 percent by weight of total composition.The ethylene/carboxylic acid interpolymer can have an acid content fromabout 3 percent by weight of the interpolymer to about 50 percent byweight of the interpolymer.

In some embodiments, the gasket comprises a slip agent that comprises aprimary amide agent and a secondary amide agent, together comprisingfrom about 0.05 percent by weight of the total composition to about 5percent by weight of the total composition. The primary amide agent canbe present at a level at least twice that of the secondary amide agent.In some embodiments, the slip agent comprises a silane compound.

In other embodiments, the gasket is foamed using a foaming agent, suchas physical blowing agents, gaseous blowing agents and chemical blowingagents. The chemical blowing agents include, but are not limited to,sodium bicarbonate, dinitrosopentamethylenetetramine, sulfonylhydrazides, azodicarbonamide, p-toluenesulfonyl semicarbazide,5-phenyltetrazole, diisopropylhydrazodicarboxylate,5-phenyl-3,6-dihydro-1,3,4-oxadiazin-2-one, and sodium borohydride.

In yet other embodiments, the foaming agent is a gaseous blowing agentselected from the group consisting of carbon dioxide and nitrogen. Inanother embodiment, the foaming agent is a physical blowing agentselected from a group consisting of pentanes, hexanes, heptanes,benzene, toluene, dichloromethane, trichloromethane, trichloroethylene,tetrachloromethane, 1,2-dichloroethane, trichlorofluoromethane,1,1,2-trichlorotrifluoroethane, methanol, ethanol, 2-propanol, ethylether, isopropyl ether, acetone, methyl ethyl ketone, and methylenechloride; isobutane and n-butane, 1,1-difluoroethane.

In some embodiments, the ethelyne/α-olefin interpolymer in the gasketprovided herein comprises from about 25 to about 35% by weight of thecomposition, the other polymer comprises from about 55 to about 65% byweight of the composition, and the slip agent comprises from about 1 toabout 3% by weight of the composition.

In other embodiments, the gasket comprises the polymer compositionprovided herein that has either a static coefficient of friction or adynamic coefficient of friction, or both, of less than about 1 or ofabout 0.6 or less.

In some embodiments, the compostion has a melt index greater than orequal to about 5 g/10 minutes and a 70° C. compression set of less than70% and and change in compression set between 23° C. and 70° C. is lessthan 55%.

In other embodiments, the gasket provided herein comprises the polymercomposition that comprises at least one ethylene/α-olefin interpolymerat about 80 to about 97.5 weight percent of the total weight of thecomposition; about 2 to about 15 weight percent of at least oneethylene/carboxylic acid interpolymer or ionomer thereof and at leastone slip agent, wherein the weight percentage of the two interpolymersare based on the total weight of composition.

Additional aspects of the invention and characteristics and propertiesof various embodiments of the invention become apparent with thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the melting point/density relationship for the inventivepolymers (represented by diamonds) as compared to traditional randomcopolymers (represented by circles) and Ziegler-Natta copolymers(represented by triangles).

FIG. 2 shows plots of delta DSC-CRYSTAF as a function of DSC MeltEnthalpy for various polymers. The diamonds represent randomethylene/octene copolymers; the squares represent polymer examples 1-4;the triangles represent polymer examples 5-9; and the circles representpolymer examples 10-19. The “X” symbols represent polymer examplesA*-F*.

FIG. 3 shows the effect of density on elastic recovery for unorientedfilms comprising inventive interpolymers (represented by the squares andcircles) and traditional copolymers (represented by the triangles whichare various Dow AFFINITY® polymers). The squares represent inventiveethylene/butene copolymers; and the circles represent inventiveethylene/octene copolymers.

FIG. 4 is a plot of octene content of TREF fractionatedethylene/1-octene copolymer fractions versus TREF elution temperature ofthe fraction for the polymer of Example 5 (represented by the circles)and Comparative Examples E* and F* (represented by the “X” symbols). Thediamonds represent traditional random ethylene/octene copolymers.

FIG. 5 is a plot of octene content of TREF fractionatedethylene/1-octene copolymer fractions versus TREF elution temperature ofthe fraction for the polymer of Example 5 (curve 1) and for ComparativeExample F* (curve 2). The squares represent Example F*; and thetriangles represent Example 5.

FIG. 6 is a graph of the log of storage modulus as a function oftemperature for comparative ethylene/1-octene copolymer (curve 2) andethylene/propylene copolymer (curve 3) and for two ethylene/1-octeneblock copolymers of the invention made with differing quantities ofchain shuttling agent (curves 1).

FIG. 7 shows a plot of TMA (1 mm) versus flex modulus for some inventivepolymers (represented by the diamonds), as compared to some knownpolymers. The triangles represent various Dow VERSIFY® polymers; thecircles represent various random ethylene/styrene copolymers; and thesquares represent various Dow AFFINITY® polymers.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION General Definitions

“Polymer” means a polymeric compound prepared by polymerizing monomers,whether of the same or a different type. The generic term “polymer”embraces the terms “homopolymer,” “copolymer,” “terpolymer” as well as“interpolymer.”

“Interpolymer” means a polymer prepared by the polymerization of atleast two different types of monomers. The generic term “interpolymer”includes the term “copolymer” (which is usually employed to refer to apolymer prepared from two different monomers) as well as the term“terpolymer” (which is usually employed to refer to a polymer preparedfrom three different types of monomers). It also encompasses polymersmade by polymerizing four or more types of monomers.

The term “ethylene/α-olefin interpolymer” refers to polymers withethylene being the majority mole fraction of the whole polymer.Preferably, ethylene comprises at least 50 mole percent of the wholepolymer, more preferably at least 60 mole percent, at least 70 molepercent, or at least 80 mole percent, with the reminder of the wholepolymer comprising at least another comonomer. For ethylene/octenecopolymers, the preferred composition includes an ethylene contentgreater than about 80 mole percent with a octene content of equal to orless than about 20 mole percent. In some embodiments, theethylene/α-olefin interpolymers do not include those produced in lowyields or in a minor amount or as a by-product of a chemical process.While the ethylene/α-olefin interpolymers can be blended with one ormore polymers, the as-produced ethylene/α-olefin interpolymers aresubstantially pure and constitute the major component of apolymerization process.

The ethylene/α-olefin interpolymers comprise ethylene and one or morecopolymerizable α-olefin comonomers in polymerized form, characterizedby multiple (i.e., two or more) blocks or segments of two or morepolymerized monomer units differing in chemical or physical properties(block interpolymer), preferably a multi-block copolymer. In someembodiments, the multi-block copolymer can be represented by thefollowing formula:

(AB)_(n)

where n is at least 1, preferably an integer greater than 1, such as 2,3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, or higher, “A”represents a hard block or segment and “B” represents a soft block orsegment. Preferably, As and Bs are linked in a linear fashion, not in abranched or a star fashion. “Hard” segments refer to blocks ofpolymerized units in which ethylene is present in an amount greater than95 weight percent, and preferably greater than 98 weight percent. Inother words, the comonomer content in the hard segments is less than 5weight percent, and preferably less than 2 weight percent. In someembodiments, the hard segments comprises all or substantially allethylene. “Soft” segments, on the other hand, refer to blocks ofpolymerized units in which the comonomer content is greater than 5weight percent, preferably greater than 8 weight percent, greater than10 weight percent, or greater than 15 weight percent. In someembodiments, the comonomer content in the soft segments can be greaterthan 20 weight percent, greater than 25 eight percent, greater than 30weight percent, greater than 35 weight percent, greater than 40 weightpercent, greater than 45 weight percent, greater than 50 weight percent,or greater than 60 weight percent.

In some embodiments, A blocks and B blocks are randomly distributedalong the polymer chain. In other words, the block copolymers do nothave a structure like:

AAA-AA-BBB-BB

In other embodiments, the block copolymers do not have a third type ofblock. In still other embodiments, each of block A and block B hasmonomers or comonomers randomly distributed within the block. In otherwords, neither block A nor block B comprises two or more segments (orsub-blocks) of distinct composition, such as a tip segment, which has adifferent composition than the rest of the block.

The term “crystalline” if employed, refers to a polymer that possesses afirst order transition or crystalline melting point (Tm) as determinedby differential scanning calorimetry (DSC) or equivalent technique. Theterm may be used interchangeably with the term “semicrystalline”. Theterm “amorphous” refers to a polymer lacking a crystalline melting pointas determined by differential scanning calorimetry (DSC) or equivalenttechnique.

The term “multi-block copolymer” or “segmented copolymer” refers to apolymer comprising two or more chemically distinct regions or segments(referred to as “blocks”) preferably joined in a linear manner, that is,a polymer comprising chemically differentiated units which are joinedend-to-end with respect to polymerized ethylenic functionality, ratherthan in pendent or grafted fashion. In a preferred embodiment, theblocks differ in the amount or type of comonomer incorporated therein,the density, the amount of crystallinity, the crystallite sizeattributable to a polymer of such composition, the type or degree oftacticity (isotactic or syndiotactic), regio-regularity orregio-irregularity, the amount of branching, including long chainbranching or hyper-branching, the homogeneity, or any other chemical orphysical property. The multi-block copolymers are characterized byunique distributions of both polydispersity index (PDI or Mw/Mn), blocklength distribution, and/or block number distribution due to the uniqueprocess making of the copolymers. More specifically, when produced in acontinuous process, the polymers desirably possess PDI from 1.7 to 2.9,preferably from 1.8 to 2.5, more preferably from 1.8 to 2.2, and mostpreferably from 1.8 to 2.1. When produced in a batch or semi-batchprocess, the polymers possess PDI from 1.0 to 2.9, preferably from 1.3to 2.5, more preferably from 1.4 to 2.0, and most preferably from 1.4 to1.8.

The term “polar polymer” or “polar interpolymer” refers to a polymerthat includes at least one polar monomer. A polar monomer is apolymerizable ethylenically unsaturated compound bearing a polar grouphaving a group moment in the range from about 1.4 to about 4.4 Debyeunits as determined by Smyth, C. P., Dielectric Behavior and Structure,McGraw-Hill Book Company, Inc., New York (1955). Exemplary polar groupsinclude —CN, —NO₂, —OH, —Br, —Cl, —NH₂, —C(O)OR and —OC(O)R wherein R isalkyl or aryl. Preferably, the polar monomer is an ethylenicallyunsaturated nitrile such as acrylonitrile, methacrylonitrile andfumaronitrile, and alkyl esters of α, β-ethylenically unsaturated acids,e.g., alkyl acrylates and methacrylates, methyl acrylate, butyl acrylateand methyl methacrylate, with acrylonitrile and methyl methacrylatebeing most preferred.

In the following description, all numbers disclosed herein areapproximate values, regardless whether the word “about” or “approximate”is used in connection therewith. They may vary by 1 percent, 2 percent,5 percent, or, sometimes, 10 to 20 percent. Whenever a numerical rangewith a lower limit, R^(L) and an upper limit, R^(U), is disclosed, anynumber falling within the range is specifically disclosed. Inparticular, the following numbers within the range are specificallydisclosed: R=R^(L)+k*(R^(U)−R^(L)), wherein k is a variable ranging from1 percent to 100 percent with a 1 percent increment, i.e., k is 1percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent,51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98percent, 99 percent, or 100 percent. Moreover, any numerical rangedefined by two R numbers as defined in the above is also specificallydisclosed.

Embodiments of the invention provide various polymer blend compositonsand gaskets, bottle cap liners, and enclosures made therefrom. Thepolymer compositions comprise at least one ethylene/α-olefininterpolymer and at least one other polymer which is different than theethylene/α-olefin interpolymer. The other polymer can be a secondethylene/α-olefin interpolymer, an elastomer, a polyolefin, a polarpolymer, and an ethylene/carboxylic acid interpolymer or an ionomerthereof. When the other polymer is a second ethylene/α-olefininterpolymer, the two ethylene/α-olefin interpolymers in the polymerblend compositions are different. The polymer blends possess uniquephysical and mechanical properties that are suitable for making moldedarticles for a variety of applications. Preferably, theethylene/α-olefin interpolymers are a multi-block copolymer comprisingat least one soft block and at least one hard block. In someembodiments, the blends have relatively low modulus, while maintainingrelatively high heat resistance. Such balance of properties makes theblended suitable for making flexible molded articles. The moldedarticles should have an upper use or service temperature of at least 40°C., at least 50° C., at least 60° C., at least 80° C., or at least 90°C.

The term “different” when referring to two polymers means that the twopolymers differ in composition (monomer or comonomer type, monomer orcomonomer content, etc.), structure, property, or a combination thereof.Two polymers also are considered different if they have a differentmolecular weight, even though they have the same structure andcomposition. Conversely, two polymer are considered different if theyhave a different structure even if they have the same composition andmolecular weight. For example, a homogeneous ethylene/octene copolymermade by a metallocene catalyst is different than a heterogeneousethylene/octene copolymer made by a Zieglar-Natta catalyst, even if theyhave identifical comonomer content and molecular weight. Morever, twoethylene/α-olefin interpolymers can differ in the melt index and/oroverall density.

Some gaskets should withstand temperatures higher than room temperature(about 25° C.) for brief times, particularly where the application is a“hot fill” application. For example, products which undergopasteurization should have gaskets that have melting points greater than100° C. Because the ethylene/α-olefin interpolymers described below havea unique melting point-density relationship, such interpolymers with awide range of densities can be used to make gaskets. In contrast tohomogeneously branched linear or homogeneously branched substantiallylinear olefin polymers which have lower melting points as densitylowers, the ethylene/α-olefin interpolymers used in embodiments of theinvention have melting points substantially independent of density.

The density of the ethylene/α-olefin interpolymers used in embodimentsof the invention is measured in accordance with ASTM D-792 and isgenerally from about 0.85 g/cm³ to about 0.96 g/cm³, preferably fromabout 0.87 g/cm³ to about 0.92 g/cm³, and especially from about 0.89g/cm³ to about 0.915 g/cm³.

The Food and Drug Administration (FDA) currently limits hexaneextractables for polyethylene for food contact to not more than 5.5%.The method is described in FDA regulation 21 CFR Ch. 1 (Apr. 1, 1994Edition) §177.1520, pages 252-253. Even though molecular weightdistribution influences hexane extractables, larger amounts ofcomonomer, especially for heterogeneous polyethylene copolymers, causeshigher levels of hexane extractables. For example, heterogeneousethylene/1-octene linear polyethylene having densities from about 0.9017to about 0.91 g/cm³ generally have hexane extractables greater than 5%.In contrast, ethylene/1-octene copolymers described below havingdensities at least as low as about 0.8976 g/cm³ have hexane extractablesless than 5%, preferably less than about 4% and especially less thanabout 2%.

Ethylene/α-Olefin Interpolymers

The ethylene/α-olefin interpolymers used in embodiments of the invention(also referred to as “inventive interpolymer” or “inventive polymer”)comprise ethylene and one or more copolymerizable α-olefin comonomers inpolymerized form, characterized by multiple blocks or segments of two ormore polymerized monomer units differing in chemical or physicalproperties (block interpolymer), preferably a multi-block copolymer. Theethylene/α-olefin interpolymers are characterized by one or more of theaspects described as follows.

In one aspect, the ethylene/α-olefin interpolymers used in embodimentsof the invention have a M_(w)/M_(n) from about 1.7 to about 3.5 and atleast one melting point, T_(m), in degrees Celsius and density, d, ingrams/cubic centimeter, wherein the numerical values of the variablescorrespond to the relationship:

T _(m)>−2002.9+4538.5(d)−2422.2(d)², and preferably

T _(m)≧−6288.1+13141(d)−6720.3(d)², and more preferably

T _(m)≧858.91−1825.3(d)+1112.8(d)².

Such melting point/density relationship is illustrated in FIG. 1. Unlikethe traditional random copolymers of ethylene/α-olefins whose meltingpoints decrease with decreasing densities, the inventive interpolymers(represented by diamonds) exhibit melting points substantiallyindependent of the density, particularly when density is between about0.87 g/cc to about 0.95 g/cc. For example, the melting point of suchpolymers are in the range of about 110° C. to about 130° C. when densityranges from 0.875 g/cc to about 0.945 g/cc. In some embodiments, themelting point of such polymers are in the range of about 115° C. toabout 125° C. when density ranges from 0.875 g/cc to about 0.945 g/cc.

In another aspect, the ethylene/α-olefin interpolymers comprise, inpolymerized form, ethylene and one or more α-olefins and arecharacterized by a ΔT, in degree Celsius, defined as the temperature forthe tallest Differential Scanning Calorimetry (“DSC”) peak minus thetemperature for the tallest Crystallization Analysis Fractionation(“CRYSTAF”) peak and a heat of fusion in J/g, ΔH, and ΔT and ΔH satisfythe following relationships:

ΔT>−0.1299(ΔH)+62.81, and preferably

ΔT≧−0.1299(ΔH)+64.38, and more preferably

ΔT≧−0.1299(ΔH)+65.95,

for ΔH up to 130 J/g. Moreover, ΔT is equal to or greater than 48° C.for ΔH greater than 130 J/g. The CRYSTAF peak is determined using atleast 5 percent of the cumulative polymer (that is, the peak mustrepresent at least 5 percent of the cumulative polymer), and if lessthan 5 percent of the polymer has an identifiable CRYSTAF peak, then theCRYSTAF temperature is 30° C., and ΔH is the numerical value of the heatof fusion in J/g. More preferably, the highest CRYSTAF peak contains atleast 10 percent of the cumulative polymer. FIG. 2 shows plotted datafor inventive polymers as well as comparative examples. Integrated peakareas and peak temperatures are calculated by the computerized drawingprogram supplied by the instrument maker. The diagonal line shown forthe random ethylene octene comparative polymers corresponds to theequation ΔT=−0.1299 (ΔH)+62.81.

In yet another aspect, the ethylene/α-olefin interpolymers have amolecular fraction which elutes between 40° C. and 130° C. whenfractionated using Temperature Rising Elution Fractionation (“TREF”),characterized in that said fraction has a molar comonomer contenthigher, preferably at least 5 percent higher, more preferably at least10 percent higher, than that of a comparable random ethyleneinterpolymer fraction eluting between the same temperatures, wherein thecomparable random ethylene interpolymer contains the same comonomer(s),and has a melt index, density, and molar comonomer content (based on thewhole polymer) within 10 percent of that of the block interpolymer.Preferably, the Mw/Mn of the comparable interpolymer is also within 10percent of that of the block interpolymer and/or the comparableinterpolymer has a total comonomer content within 10 weight percent ofthat of the block interpolymer.

In still another aspect, the ethylene/α-olefin interpolymers arecharacterized by an elastic recovery, Re, in percent at 300 percentstrain and 1 cycle measured on a compression-molded film of anethylene/α-olefin interpolymer, and has a density, d, in grams/cubiccentimeter, wherein the numerical values of Re and d satisfy thefollowing relationship when ethylene/α-olefin interpolymer issubstantially free of a cross-linked phase:

Re>1481−1629(d); and preferably

Re≧1491−1629(d); and more preferably

Re≧1501−1629(d); and even more preferably

Re≧1511−1629(d).

FIG. 3 shows the effect of density on elastic recovery for unorientedfilms made from certain inventive interpolymers and traditional randomcopolymers. For the same density, the inventive interpolymers havesubstantially higher elastic recoveries.

In some embodiments, the ethylene/α-olefin interpolymers have a tensilestrength above 10 MPa, preferably a tensile strength ≧11 MPa, morepreferably a tensile strength ≧13 MPa and/or an elongation at break ofat least 600 percent, more preferably at least 700 percent, highlypreferably at least 800 percent, and most highly preferably at least 900percent at a crosshead separation rate of 11 cm/minute.

In other embodiments, the ethylene/α-olefin interpolymers have (1) astorage modulus ratio, G′(25° C.)/G′(100° C.), of from 1 to 50,preferably from 1 to 20, more preferably from 1 to 10; and/or (2) a 70°C. compression set of less than 80 percent, preferably less than 70percent, especially less than 60 percent, less than 50 percent, or lessthan 40 percent, down to a compression set of 0 percent.

In still other embodiments, the ethylene/α-olefin interpolymers have a70° C. compression set of less than 80 percent, less than 70 percent,less than 60 percent, or less than 50 percent. Preferably, the 70° C.compression set of the interpolymers is less than 40 percent, less than30 percent, less than 20 percent, and may go down to about 0 percent.

In some embodiments, the ethylene/α-olefin interpolymers have a heat offusion of less than 85 J/g and/or a pellet blocking strength of equal toor less than 100 pounds/foot² (4800 Pa), preferably equal to or lessthan 50 lbs/ft² (2400 Pa), especially equal to or less than 5 lbs/ft²(240 Pa), and as low as 0 lbs/ft² (0 Pa).

In other embodiments, the ethylene/α-olefin interpolymers comprise, inpolymerized form, at least 50 mole percent ethylene and have a 70° C.compression set of less than 80 percent, preferably less than 70 percentor less than 60 percent, most preferably less than 40 to 50 percent anddown to close zero percent.

In some embodiments, the multi-block copolymers possess a PDI fitting aSchultz-Flory distribution rather than a Poisson distribution. Thecopolymers are further characterized as having both a polydisperse blockdistribution and a polydisperse distribution of block sizes andpossessing a most probable distribution of block lengths. Preferredmulti-block copolymers are those containing 4 or more blocks or segmentsincluding terminal blocks. More preferably, the copolymers include atleast 5, 10 or 20 blocks or segments including terminal blocks .

Comonomer content may be measured using any suitable technique, withtechniques based on nuclear magnetic resonance (“NMR”) spectroscopypreferred. Moreover, for polymers or blends of polymers havingrelatively broad TREF curves, the polymer desirably is firstfractionated using TREF into fractions each having an eluted temperaturerange of 10° C. or less. That is, each eluted fraction has a collectiontemperature window of 10° C. or less. Using this technique, said blockinterpolymers have at least one such fraction having a higher molarcomonomer content than a corresponding fraction of the comparableinterpolymer.

In another aspect, the inventive polymer is an olefin interpolymer,preferably comprising ethylene and one or more copolymerizablecomonomers in polymerized form, characterized by multiple blocks (i.e.,at least two blocks) or segments of two or more polymerized monomerunits differing in chemical or physical properties (blockedinterpolymer), most preferably a multi-block copolymer, said blockinterpolymer having a peak (but not just a molecular fraction) whichelutes between 40° C. and 130° C. (but without collecting and/orisolating individual fractions), characterized in that said peak, has acomonomer content estimated by infra-red spectroscopy when expandedusing a full width/half maximum (FWHM) area calculation, has an averagemolar comonomer content higher, preferably at least 5 percent higher,more preferably at least 10 percent higher, than that of a comparablerandom ethylene interpolymer peak at the same elution temperature andexpanded using a full width/half maximum (FWHM) area calculation,wherein said comparable random ethylene interpolymer has the samecomonomer(s) and has a melt index, density, and molar comonomer content(based on the whole polymer) within 10 percent of that of the blockedinterpolymer. Preferably, the Mw/Mn of the comparable interpolymer isalso within 10 percent of that of the blocked interpolymer and/or thecomparable interpolymer has a total comonomer content within 10 weightpercent of that of the blocked interpolymer. The full width/half maximum(FWHM) calculation is based on the ratio of methyl to methylene responsearea [CH₃/CH₂] from the ATREF infra-red detector, wherein the tallest(highest) peak is identified from the base line, and then the FWHM areais determined. For a distribution measured using an ATREF peak, the FWHMarea is defined as the area under the curve between T₁ and T₂, where T₁and T₂ are points determined, to the left and right of the ATREF peak,by dividing the peak height by two, and then drawing a line horizontalto the base line, that intersects the left and right portions of theATREF curve. A calibration curve for comonomer content is made usingrandom ethylene/α-olefin copolymers, plotting comonomer content from NMRversus FWHM area ratio of the TREF peak. For this infra-red method, thecalibration curve is generated for the same comonomer type of interest.The comonomer content of TREF peak of the inventive polymer can bedetermined by referencing this calibration curve using its FWHMmethyl:methylene area ratio [CH₃/CH₂] of the TREF peak.

Comonomer content may be measured using any suitable technique, withtechniques based on nuclear magnetic resonance (NMR) spectroscopypreferred. Using this technique, said blocked interpolymers has highermolar comonomer content than a corresponding comparable interpolymer.

Preferably, for interpolymers of ethylene and 1-octene, the blockinterpolymer has a comonomer content of the TREF fraction elutingbetween 40 and 130° C. greater than or equal to the quantity (−0.2013)T+20.07, more preferably greater than or equal to the quantity (−0.2013)T+21.07, where T is the numerical value of the peak elution temperatureof the TREF fraction being compared, measured in ° C.

FIG. 4 graphically depicts an embodiment of the block interpolymers ofethylene and 1-octene where a plot of the comonomer content versus TREFelution temperature for several comparable ethylene/1-octeneinterpolymers (random copolymers) are fit to a line representing(−0.2013) T+20.07 (solid line). The line for the equation (−0.2013)T+21.07 is depicted by a dotted line. Also depicted are the comonomercontents for fractions of several block ethylene/1-octene interpolymersof the invention (multi-block copolymers). All of the block interpolymerfractions have significantly higher 1-octene content than either line atequivalent elution temperatures. This result is characteristic of theinventive intelpolymer and is believed to be due to the presence ofdifferentiated blocks within the polymer chains, having both crystallineand amorphous nature.

FIG. 5 graphically displays the TREF curve and comonomer contents ofpolymer fractions for Example 5 and Comparative Example F* to bediscussed below. The peak eluting from 40 to 130° C., preferably from60° C. to 95° C. for both polymers is fractionated into three parts,each part eluting over a temperature range of less than 10° C. Actualdata for Example 5 is represented by triangles. The skilled artisan canappreciate that an appropriate calibration curve may be constructed forinterpolymers containing different comonomers and a line used as acomparison fitted to the TREF values obtained from interpolymers of thesame monomers, preferably random copolymers made using a metallocene orother homogeneous catalyst composition. Inventive interpolymers arecharacterized by a molar comonomer content greater than the valuedetermined from the calibration curve at the same TREF elutiontemperature, preferably at least 5 percent greater, more preferably atleast 10 percent greater.

In addition to the above aspects and properties described herein, theinventive polymers can be characterized by one or more additionalcharacteristics. In one aspect, the inventive polymer is an olefininterpolymer, preferably comprising ethylene and one or morecopolymerizable comonomers in polymerized form, characterized bymultiple blocks or segments of two or more polymerized monomer unitsdiffering in chemical or physical properties (blocked interpolymer),most preferably a multi-block copolymer, said block interpolymer havinga molecular fraction which elutes between 40° C. and 130° C., whenfractionated using TREF increments, characterized in that said fractionhas a molar comonomer content higher, preferably at least 5 percenthigher, more preferably at least 10, 15, 20 or 25 percent higher, thanthat of a comparable random ethylene interpolymer fraction elutingbetween the same temperatures, wherein said comparable random ethyleneinterpolymer comprises the same comonomer(s), preferably it is the samecomonomer(s), and a melt index, density, and molar comonomer content(based on the whole polymer) within 10 percent of that of the blockedinterpolymer. Preferably, the Mw/Mn of the comparable interpolymer isalso within 10 percent of that of the blocked interpolymer and/or thecomparable interpolymer has a total comonomer content within 10 weightpercent of that of the blocked interpolymer.

Preferably, the above interpolymers are interpolymers of ethylene and atleast one α-olefin, especially those interpolymers having a wholepolymer density from about 0.855 to about 0.935 g/cm³, and moreespecially for polymers having more than about 1 mole percent comonomer,the blocked interpolymer has a comonomer content of the TREF fractioneluting between 40 and 130° C. greater than or equal to the quantity(−0.1356) T+13.89, more preferably greater than or equal to the quantity(−0.1356) T+14.93, and most preferably greater than or equal to thequantity (−0.2013)T+21.07, where T is the numerical value of the peakATREF elution temperature of the TREF fraction being compared, measuredin ° C.

Preferably, for the above interpolymers of ethylene and at least onealpha-olefin especially those interpolymers having a whole polymerdensity from about 0.855 to about 0.935 g/cm³, and more especially forpolymers having more than about 1 mole percent comonomer, the blockedinterpolymer has a comonomer content of the TREF fraction elutingbetween 40 and 130° C. greater than or equal to the quantity (−0.2013)T+20.07, more preferably greater than or equal to the quantity (−0.2013)T+21.07, where T is the numerical value of the peak elution temperatureof the TREF fraction being compared, measured in ° C.

In still another aspect, the inventive polymer is an olefininterpolymer, preferably comprising ethylene and one or morecopolymerizable comonomers in polymerized form, characterized bymultiple blocks or segments of two or more polymerized monomer unitsdiffering in chemical or physical properties (blocked interpolymer),most preferably a multi-block copolymer, said block interpolymer havinga molecular fraction which elutes between 40° C. and 130° C., whenfractionated using TREF increments, characterized in that every fractionhaving a comonomer content of at least about 6 mole percent, has amelting point greater than about 100° C. For those fractions having acomonomer content from about 3 mole percent to about 6 mole percent,every fraction has a DSC melting point of about 110° C. or higher. Morepreferably, said polymer fractions, having at least 1 mol percentcomonomer, has a DSC melting point that corresponds to the equation:

T _(m)≧(−5.5926) (mol percent comonomer in the fraction)+135.90.

In yet another aspect, the inventive polymer is an olefin interpolymer,preferably comprising ethylene and one or more copolymerizablecomonomers in polymerized form, characterized by multiple blocks orsegments of two or more polymerized monomer units differing in chemicalor physical properties (blocked interpolymer), most preferably amulti-block copolymer, said block interpolymer having a molecularfraction which elutes between 40° C. and 130° C., when fractionatedusing TREF increments, characterized in that every fraction that has anATREF elution temperature greater than or equal to about 76° C., has amelt enthalpy (heat of fusion) as measured by DSC, corresponding to theequation:

Heat of fusion (J/gm)≦(3.1718)(ATREF elution temperature inCelsius)−136.58,

The inventive block interpolymers have a molecular fraction which elutesbetween 40° C. and 130° C., when fractionated using TREF increments,characterized in that every fraction that has an ATREF elutiontemperature between 40° C. and less than about 76° C., has a meltenthalpy (heat of fusion) as measured by DSC, corresponding to theequation:

Heat of fusion (J/gm)≦(1.1312)(ATREF elution temperature inCelsius)+22.97.

ATREF Peak Comonomer Composition Measurement by Infra-Red Detector

The comonomer composition of the TREF peak can be measured using an IR4infra-red detector available from Polymer Char, Valencia, Spain(http://www.polymerchar.com/).

The “composition mode” of the detector is equipped with a measurementsensor (CH₂) and composition sensor (CH₃) that are fixed narrow bandinfra-red filters in the region of 2800-3000 cm⁻¹. The measurementsensor detects the methylene (CH₂) carbons on the polymer (whichdirectly relates to the polymer concentration in solution) while thecomposition sensor detects the methyl (CH₃) groups of the polymer. Themathematical ratio of the composition signal (CH₃) divided by themeasurement signal (CH₂) is sensitive to the comonomer content of themeasured polymer in solution and its response is calibrated with knownethylene alpha-olefin copolymer standards.

The detector when used with an ATREF instrument provides both aconcentration (CH₂) and composition (CH₃) signal response of the elutedpolymer during the TREF process. A polymer specific calibration can becreated by measuring the area ratio of the CH₃ to CH₂ for polymers withknown comonomer content (preferably measured by NMR). The comonomercontent of an ATREF peak of a polymer can be estimated by applying a thereference calibration of the ratio of the areas for the individual CH₃and CH₂ response (i.e. area ratio CH₃/CH₂ versus comonomer content).

The area of the peaks can be calculated using a full width/half maximum(FWHM) calculation after applying the appropriate baselines to integratethe individual signal responses from the TREF chromatogram. The fullwidth/half maximum calculation is based on the ratio of methyl tomethylene response area [CH₃/CH₂] from the ATREF infra-red detector,wherein the tallest (highest) peak is identified from the base line, andthen the FWHM area is determined. For a distribution measured using anATREF peak, the FWHM area is defined as the area under the curve betweenT1 and T2, where T1 and T2 are points determined, to the left and rightof the ATREF peak, by dividing the peak height by two, and then drawinga line horizontal to the base line, that intersects the left and rightportions of the ATREF curve.

The application of infra-red spectroscopy to measure the comonomercontent of polymers in this ATREF-infra-red method is, in principle,similar to that of GPC/FTIR systems as described in the followingreferences: Markovich, Ronald P.; Hazlitt, Lonnie G.; Smith, Linley;“Development of gel-permeation chromatography-Fourier transform infraredspectroscopy for characterization of ethylene-based polyolefincopolymers”. Polymeric Materials Science and Engineering (1991), 65,98-100.; and Deslauriers, P. J.; Rohlfing, D. C.; Shieh, E. T.;“Quantifying short chain branching microstructures in ethylene-1-olefincopolymers using size exclusion chromatography and Fourier transforminfrared spectroscopy (SEC-FTIR)”, Polymer (2002), 43, 59-170., both ofwhich are incorporated by reference herein in their entirety.

In other embodiments, the inventive ethylene/α-olefin interpolymer ischaracterized by an average block index, ABI, which is greater than zeroand up to about 1.0 and a molecular weight distribution, M_(w)/M_(n),greater than about 1.3. The average block index, ABI, is the weightaverage of the block index (“BI”) for each of the polymer fractionsobtained in preparative TREF from 20° C. and 110° C., with an incrementof 5° C.:

ABI=Σ(w _(i) BI _(i))

where BI_(i) is the block index for the ith fraction of the inventiveethylene/α-olefin interpolymer obtained in preparative TREF, and wi isthe weight percentage of the ith fraction.

For each polymer fraction, BI is defined by one of the two followingequations (both of which give the same BI value):

${BI} = {{\frac{{1/T_{X}} - {1/T_{XO}}}{{1/T_{A}} - {1/T_{AB}}}\mspace{14mu} {or}\mspace{14mu} {BI}} = {- \frac{{LnP}_{X} - {LnP}_{XO}}{{LnP}_{A} - {LnP}_{AB}}}}$

where T_(X) is the preparative ATREF elution temperature for the ithfraction (preferably expressed in Kelvin), P_(X) is the ethylene molefraction for the ith fraction, which can be measured by NMR or IR asdescribed above. P_(AB) is the ethylene mole fraction of the wholeethylene/α-olefin interpolymer (before fractionation), which also can bemeasured by NMR or IR. T_(A) and P_(A) are the ATREF elution temperatureand the ethylene mole fraction for pure “hard segments” (which refer tothe crystalline segments of the interpolymer). As a first orderapproximation, the T_(A) and P_(A) values are set to those for highdensity polyethylene homopolymer, if the actual values for the “hardsegments” are not available. For calculations performed herein, T_(A) is372° K, P_(A) is 1.

T_(AB) is the ATREF temperature for a random copolymer of the samecomposition and having an ethylene mole fraction of P_(AB). T_(AB) canbe calculated from the following equation:

Ln P _(AB) =α/T _(AB)+β

where α and β are two constants which can be determined by calibrationusing a number of known random ethylene copolymers. It should be notedthat α and β may vary from instrument to instrument. Moreover, one wouldneed to create their own calibration curve with the polymer compositionof interest and also in a similar molecular weight range as thefractions. There is a slight molecular weight effect. If the calibrationcurve is obtained from similar molecular weight ranges, such effectwould be essentially negligible. In some embodiments, random ethylenecopolymers satisfy the following relationship:

Ln P=−237.83/T _(ATREF)+0.639

T_(XO) is the ATREF temperature for a random copolymer of the samecomposition and having an ethylene mole fraction of P_(X). T_(XO) can becalculated from LnP_(X)=α/T_(XO)+β. Conversely, P_(XO) is the ethylenemole fraction for a random copolymer of the same composition and havingan ATREF temperature of T_(X), which can be calculated from LnP_(XO)=α/T_(X)+β.

Once the block index (BI) for each preparative TREF fraction isobtained, the weight average block index, ABI, for the whole polymer canbe calculated. In some embodiments, ABI is greater than zero but lessthan about 0.3 or from about 0.1 to about 0.3. In other embodiments, ABIis greater than about 0.3 and up to about 1.0. Preferably, ABI should bein the range of from about 0.4 to about 0.7, from about 0.5 to about0.7, or from about 0.6 to about 0.9. In some embodiments, ABI is in therange of from about 0.3 to about 0.9, from about 0.3 to about 0.8, orfrom about 0.3 to about 0.7, from about 0.3 to about 0.6, from about 0.3to about 0.5, or from about 0.3 to about 0.4. In other embodiments, ABIis in the range of from about 0.4 to about 1.0, from about 0.5 to about1.0, or from about 0.6 to about 1.0, from about 0.7 to about 1.0, fromabout 0.8 to about 1.0, or from about 0.9 to about 1.0.

Another characteristic of the inventive ethylene/α-olefin interpolymeris that the inventive ethylene/α-olefin interpolymer comprises at leastone polymer fraction which can be obtained by preparative TREF, whereinthe fraction has a block index greater than about 0.1 and up to about1.0 and a molecular weight distribution, M_(w)/M_(n), greater than about1.3. In some embodiments, the polymer fraction has a block index greaterthan about 0.6 and up to about 1.0, greater than about 0.7 and up toabout 1.0, greater than about 0.8 and up to about 1.0, or greater thanabout 0.9 and up to about 1.0. In other embodiments, the polymerfraction has a block index greater than about 0.1 and up to about 1.0,greater than about 0.2 and up to about 1.0, greater than about 0.3 andup to about 1.0, greater than about 0.4 and up to about 1.0, or greaterthan about 0.4 and up to about 1.0. In still other embodiments, thepolymer fraction has a block index greater than about 0.1 and up toabout 0.5, greater than about 0.2 and up to about 0.5, greater thanabout 0.3 and up to about 0.5, or greater than about 0.4 and up to about0.5. In yet other embodiments, the polymer fraction has a block indexgreater than about 0.2 and up to about 0.9, greater than about 0.3 andup to about 0.8, greater than about 0.4 and up to about 0.7, or greaterthan about 0.5 and up to about 0.6.

For copolymers of ethylene and an α-olefin, the inventive polymerspreferably possess (1) a PDI of at least 1.3, more preferably at least1.5, at least 1.7, or at least 2.0, and most preferably at least 2.6, upto a maximum value of 5.0, more preferably up to a maximum of 3.5, andespecially up to a maximum of 2.7; (2) a heat of fusion of 80 J/g orless; (3) an ethylene content of at least 50 weight percent; (4) a glasstransition temperature, T_(g), of less than −25° C., more preferablyless than −30° C., and/or (5) one and only one T_(m).

Further, the inventive polymers can have, alone or in combination withany other properties disclosed herein, a storage modulus, G′, such thatlog (G′) is greater than or equal to 400 kPa, preferably greater than orequal to 1.0 MPa, at a temperature of 100° C. Moreover, the inventivepolymers possess a relatively flat storage modulus as a function oftemperature in the range from 0 to 100° C. (illustrated in FIG. 6) thatis characteristic of block copolymers, and heretofore unknown for anolefin copolymer, especially a copolymer of ethylene and one or moreC₃₋₈ aliphatic α-olefins. (By the term “relatively flat” in this contextis meant that log G′ (in Pascals) decreases by less than one order ofmagnitude between 50 and 100° C., preferably between 0 and 100° C.).

The inventive interpolymers may be further characterized by athermomechanical analysis penetration depth of 1 mm at a temperature ofat least 90° C. as well as a flexural modulus of from 3 kpsi (20 MPa) to13 kpsi (90 MPa). Alternatively, the inventive interpolymers can have athermomechanical analysis penetration depth of 1 mm at a temperature ofat least 104° C. as well as a flexural modulus of at least 3 kpsi (20MPa). They may be characterized as having an abrasion resistance (orvolume loss) of less than 90 mm³. FIG. 7 shows the TMA (1 mm) versusflex modulus for the inventive polymers, as compared to other knownpolymers. The inventive polymers have significantly betterflexibility-heat resistance balance than the other polymers.

Additionally, the ethylene/ α-olefin interpolymers can have a meltindex, I₂, from 0.01 to 2000 g/10 minutes, preferably from 0.01 to 1000g/10 minutes, more preferably from 0.01 to 500 g/10 minutes, andespecially from 0.01 to 100 g/10 minutes. In certain embodiments, theethylene/α-olefin interpolymers have a melt index, I₂, from 0.01 to 10g/10 minutes, from 0.5 to 50 g/10 minutes, from 1 to 30 g/10 minutes,from 1 to 6 g/10 minutes or from 0.3 to 10 g/10 minutes. In certainembodiments, the melt index for the ethylene/α-olefin polymers is 1 g/10minutes, 3 g/10 minutes or 5 g/10 minutes.

The polymers can have molecular weights, M_(w), from 1,000 g/mole to5,000,000 g/mole, preferably from 1000 g/mole to 1,000,000, morepreferably from 10,000 g/mole to 500,000 g/mole, and especially from10,000 g/mole to 300,000 g/mole. The density of the inventive polymerscan be from 0.80 to 0.99 g/cm³ and preferably for ethylene containingpolymers from 0.85 g/cm³ to 0.97 g/cm³. In certain embodiments, thedensity of the ethylene/α-olefin polymers ranges from 0.860 to 0.925g/cm³ or 0.867 to 0.910 g/cm³.

The process of making the polymers has been disclosed in the followingpatent applications: U.S. Provisional Application No. 60/553,906, filedMar. 17, 2004; U.S. Provisional Application No. 60/662,937, filed Mar.17, 2005; U.S. Provisional Application No. 60/662,939, filed Mar. 17,2005; U.S. Provisional Application No. 60/5662938, filed Mar. 17, 2005;PCT Application No. PCT/US2005/008916, filed Mar. 17, 2005; PCTApplication No. PCT/US2005/008915, filed Mar. 17, 2005; and PCTApplication No. PCT/US2005/008917, filed Mar. 17, 2005, all of which areincorporated by reference herein in their entirety. For example, onesuch method comprises contacting ethylene and optionally one or moreaddition polymerizable monomers other than ethylene under additionpolymerization conditions with a catalyst composition comprising:

-   -   the admixture or reaction product resulting from combining:    -   (A) a first olefin polymerization catalyst having a high        comonomer incorporation index,    -   (B) a second olefin polymerization catalyst having a comonomer        incorporation index less than 90 percent, preferably less than        50 percent, most preferably less than 5 percent of the comonomer        incorporation index of catalyst (A), and    -   (C) a chain shuttling agent.

Representative catalysts and chain shuttling agent are as follows.

Catalyst (A1) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A2) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-methylphenyl)(1,2-phenylene-(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A3) isbis[N,N′″-(2,4,6-tri(methylphenyl)amido)ethylenediamine]hafniumdibenzyl.

Catalyst (A4) isbis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)cyclohexane-1,2-diylzirconium (IV) dibenzyl, prepared substantially according to theteachings of US-A-2004/0010103.

Catalyst (B1) is1,2-bis-(3,5-di-t-butylphenylene)(1-(N-(1-methylethyl)immino)methyl)(2-oxoyl)zirconium dibenzyl

Catalyst (B2) is 1,2-bis-(3,5-di-t-butylphenylene)(1-(N-(2-methylcyclohexyl)immino)methyl)(2-oxoyl)zirconium dibenzyl

Catalyst (C1) is(t-butylamido)dimethyl(3-N-pyrrolyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the techniques of U.S. Pat.No. 6,268,444:

Catalyst (C2) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (C3) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,8a-η-s-indacen-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (D1) is bis(dimethyldisiloxane)(indene-1-yl)zirconiumdichloride available from Sigma-Aldrich:

Shuttling Agents The shuttling agents employed include diethylzinc,di(i-butyl)zinc, di(n-hexyl)zinc, triethylaluminum, trioctylaluminum,triethylgallium, i-butylaluminum bis(dimethyl(t-butyl)siloxane),i-butylaluminum bis(di(trimethylsilyl)amide), n-octylaluminumdi(pyridine-2-methoxide), bis(n-octadecyl)i-butylaluminum,i-butylaluminum bis(di(n-pentyl)amide), n-octylaluminumbis(2,6-di-t-butylphenoxide, n-octylaluminum di(ethyl(1-naphthyl)amide),ethylaluminum bis(t-butyldimethylsiloxide), ethylaluminumdi(bis(trimethylsilyl)amide), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(dimethyl(t-butyl)siloxide, ethylzinc (2,6-diphenylphenoxide), andethylzinc (t-butoxide).

Preferably, the foregoing process takes the form of a continuoussolution process for forming block copolymers, especially multi-blockcopolymers, preferably linear multi-block copolymers of two or moremonomers, more especially ethylene and a C₃₋₂₀ olefin or cycloolefin,and most especially ethylene and a C₄₋₂₀ α-olefin, using multiplecatalysts that are incapable of interconversion. That is, the catalystsare chemically distinct. Under continuous solution polymerizationconditions, the process is ideally suited for polymerization of mixturesof monomers at high monomer conversions. Under these polymerizationconditions, shuttling from the chain shuttling agent to the catalystbecomes advantaged compared to chain growth, and multi-block copolymers,especially linear multi-block copolymers are formed in high efficiency.

The inventive interpolymers may be differentiated from conventional,random copolymers, physical blends of polymers, and block copolymersprepared via sequential monomer addition, fluxional catalysts, anionicor cationic living polymerization techniques. In particular, compared toa random copolymer of the same monomers and monomer content atequivalent crystallinity or modulus, the inventive interpolymers havebetter (higher) heat resistance as measured by melting point, higher TMApenetration temperature, higher high-temperature tensile strength,and/or higher high-temperature torsion storage modulus as determined bydynamic mechanical analysis. Compared to a random copolymer containingthe same monomers and monomer content, the inventive interpolymers havelower compression set, particularly at elevated temperatures, lowerstress relaxation, higher creep resistance, higher tear strength, higherblocking resistance, faster setup due to higher crystallization(solidification) temperature, higher recovery (particularly at elevatedtemperatures), better abrasion resistance, higher retractive force, andbetter oil and filler acceptance.

The inventive interpolymers also exhibit a unique crystallization andbranching distribution relationship. That is, the inventiveinterpolymers have a relatively large difference between the tallestpeak temperature measured using CRYSTAF and DSC as a function of heat offusion, especially as compared to random copolymers containing the samemonomers and monomer level or physical blends of polymers, such as ablend of a high density polymer and a lower density copolymer, atequivalent overall density. It is believed that this unique feature ofthe inventive interpolymers is due to the unique distribution of thecomonomer in blocks within the polymer backbone. In particular, theinventive interpolymers may comprise alternating blocks of differingcomonomer content (including homopolymer blocks). The inventiveinterpolymers may also comprise a distribution in number and/or blocksize of polymer blocks of differing density or comonomer content, whichis a Schultz-Flory type of distribution. In addition, the inventiveinterpolymers also have a unique peak melting point and crystallizationtemperature profile that is substantially independent of polymerdensity, modulus, and morphology. In a preferred embodiment, themicrocrystalline order of the polymers demonstrates characteristicspherulites and lamellae that are distinguishable from random or blockcopolymers, even at PDI values that are less than 1.7, or even less than1.5, down to less than 1.3.

Moreover, the inventive interpolymers may be prepared using techniquesto influence the degree or level of blockiness. That is the amount ofcomonomer and length of each polymer block or segment can be altered bycontrolling the ratio and type of catalysts and shuttling agent as wellas the temperature of the polymerization, and other polymerizationvariables. A surprising benefit of this phenomenon is the discovery thatas the degree of blockiness is increased, the optical properties, tearstrength, and high temperature recovery properties of the resultingpolymer are improved. In particular, haze decreases while clarity, tearstrength, and high temperature recovery properties increase as theaverage number of blocks in the polymer increases. By selectingshuttling agents and catalyst combinations having the desired chaintransferring ability (high rates of shuttling with low levels of chaintermination) other forms of polymer termination are effectivelysuppressed. Accordingly, little if any β-hydride elimination is observedin the polymerization of ethylene/α-olefin comonomer mixtures accordingto embodiments of the invention, and the resulting crystalline blocksare highly, or substantially completely, linear, possessing little or nolong chain branching.

Polymers with highly crystalline chain ends can be selectively preparedin accordance with embodiments of the invention. In elastomerapplications, reducing the relative quantity of polymer that terminateswith an amorphous block reduces the intermolecular dilutive effect oncrystalline regions. This result can be obtained by choosing chainshuttling agents and catalysts having an appropriate response tohydrogen or other chain terminating agents. Specifically, if thecatalyst which produces highly crystalline polymer is more susceptibleto chain termination (such as by use of hydrogen) than the catalystresponsible for producing the less crystalline polymer segment (such asthrough higher comonomer incorporation, regio-error, or atactic polymerformation), then the highly crystalline polymer segments willpreferentially populate the terminal portions of the polymer. Not onlyare the resulting terminated groups crystalline, but upon termination,the highly crystalline polymer forming catalyst site is once againavailable for reinitiation of polymer formation. The initially formedpolymer is therefore another highly crystalline polymer segment.Accordingly, both ends of the resulting multi-block copolymer arepreferentially highly crystalline.

The ethylene α-olefin interpolymers used in the embodiments of theinvention are preferably interpolymers of ethylene with at least oneC₃-C₂₀ α-olefin. Copolymers of ethylene and a C₃-C₂₀ α-olefin areespecially preferred. The interpolymers may further comprise C₄-C₁₈diolefin and/or alkenylbenzene. Suitable unsaturated comonomers usefulfor polymerizing with ethylene include, for example, ethylenicallyunsaturated monomers, conjugated or nonconjugated dienes, polyenes,alkenylbenzenes, etc. Examples of such comonomers include C₃-C₂₀α-olefins such as propylene, isobutylene, 1-butene, 1-hexene, 1-pentene,4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, and thelike. 1-Butene and 1-octene are especially preferred. Other suitablemonomers include styrene, halo- or alkyl-substituted styrenes,vinylbenzocyclobutane, 1,4-hexadiene, 1,7-octadiene, and naphthenics(e.g., cyclopentene, cyclohexene and cyclooctene).

While ethylene/α-olefin interpolymers are preferred polymers, otherethylene/olefin polymers may also be used. Olefins as used herein referto a family of unsaturated hydrocarbon-based compounds with at least onecarbon-carbon double bond. Depending on the selection of catalysts, anyolefin may be used in embodiments of the invention. Preferably, suitableolefins are C₃-C₂₀ aliphatic and aromatic compounds containing vinylicunsaturation, as well as cyclic compounds, such as cyclobutene,cyclopentene, dicyclopentadiene, and norbornene, including but notlimited to, norbomene substituted in the 5 and 6 position with C₁-C₂₀hydrocarbyl or cyclohydrocarbyl groups. Also included are mixtures ofsuch olefins as well as mixtures of such olefins with C₄-C₄₀ diolefincompounds.

Examples of olefin monomers include, but are not limited to propylene,isobutylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, and 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene,4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene,vinylcyclohexane, norbornadiene, ethylidene norbornene, cyclopentene,cyclohexene, dicyclopentadiene, cyclooctene, C₄-C₄₀ dienes, includingbut not limited to 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene,1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, other C₄-C₄₀ α-olefins, andthe like. In certain embodiments, the α-olefin is propylene, 1-butene,1-pentene, 1-hexene, 1-octene or a combination thereof. Although anyhydrocarbon containing a vinyl group potentially may be used inembodiments of the invention, practical issues such as monomeravailability, cost, and the ability to conveniently remove unreactedmonomer from the resulting polymer may become more problematic as themolecular weight of the monomer becomes too high.

The polymerization processes described herein are well suited for theproduction of olefin polymers comprising monovinylidene aromaticmonomers including styrene, o-methyl styrene, p-methyl styrene,t-butylstyrene, and the like. In particular, interpolymers comprisingethylene and styrene can be prepared by following the teachings herein.Optionally, copolymers comprising ethylene, styrene and a C₃-C₂₀ alphaolefin, optionally comprising a C₄-C₂₀ diene, having improved propertiescan be prepared.

Suitable non-conjugated diene monomers can be a straight chain, branchedchain or cyclic hydrocarbon diene having from 6 to 15 carbon atoms.Examples of suitable non-conjugated dienes include, but are not limitedto, straight chain acyclic dienes, such as 1,4-hexadiene, 1,6-octadiene,1,7-octadiene, 1,9-decadiene, branched chain acyclic dienes, such as5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene;3,7-dimethyl-1,7-octadiene and mixed isomers of dihydromyricene anddihydroocinene, single ring alicyclic dienes, such as1,3-cyclopentadiene; 1,4-cyclohexadiene; 1,5-cyclooctadiene and1,5-cyclododecadiene, and multi-ring alicyclic fused and bridged ringdienes, such as tetrahydroindene, methyl tetrahydroindene,dicyclopentadiene, bicyclo-(2,2,1)-hepta-2,5-diene; alkenyl, alkylidene,cycloalkenyl and cycloalkylidene norbornenes, such as5-methylene-2-norbornene (MNB); 5-propenyl-2-norbornene,5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbornene,5-cyclohexylidene-2-norbornene, 5-vinyl-2-norbornene, and norbornadiene.Of the dienes typically used to prepare EPDMs, the particularlypreferred dienes are 1,4-hexadiene (HD), 5-ethylidene-2-norbornene(ENB), 5-vinylidene-2-norbornene (VNB), 5-methylene-2-norbornene (MNB),and dicyclopentadiene (DCPD). The especially preferred dienes are5-ethylidene-2-norbornene (ENB) and 1,4-hexadiene (HD).

One class of desirable polymers that can be made in accordance withembodiments of the invention are elastomeric interpolymers of ethylene,a C₃-C₂₀ α-olefin, especially propylene, and optionally one or morediene monomers. Preferred α-olefins for use in this embodiment of thepresent invention are designated by the formula CH₂=CHR*, where R* is alinear or branched alkyl group of from 1 to 12 carbon atoms. Examples ofsuitable α-olefins include, but are not limited to, propylene,isobutylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and1-octene. A particularly preferred α-olefin is propylene. The propylenebased polymers are generally referred to in the art as EP or EPDMpolymers. Suitable dienes for use in preparing such polymers, especiallymulti-block EPDM type polymers include conjugated or non-conjugated,straight or branched chain-, cyclic- or polycyclic- dienes comprisingfrom 4 to 20 carbons. Preferred dienes include 1,4-pentadiene,1,4-hexadiene, 5-ethylidene-2-norbornene, dicyclopentadiene,cyclohexadiene, and 5-butylidene-2-norbornene. A particularly preferreddiene is 5-ethylidene-2-norbornene.

Because the diene containing polymers comprise alternating segments orblocks containing greater or lesser quantities of the diene (includingnone) and α-olefin (including none), the total quantity of diene andα-olefin may be reduced without loss of subsequent polymer properties.That is, because the diene and α-olefin monomers are preferentiallyincorporated into one type of block of the polymer rather than uniformlyor randomly throughout the polymer, they are more efficiently utilizedand subsequently the crosslink density of the polymer can be bettercontrolled. Such crosslinkable elastomers and the cured products haveadvantaged properties, including higher tensile strength and betterelastic recovery.

In some embodiments, the inventive interpolymers made with two catalystsincorporating differing quantities of comonomer have a weight ratio ofblocks formed thereby from 95:5 to 5:95. The elastomeric polymersdesirably have an ethylene content of from 20 to 90 percent, a dienecontent of from 0.1 to 10 percent, and an α-olefin content of from 10 to80 percent, based on the total weight of the polymer. Furtherpreferably, the multi-block elastomeric polymers have an ethylenecontent of from 60 to 90 percent, a diene content of from 0.1 to 10percent, and an α-olefin content of from 10 to 40 percent, based on thetotal weight of the polymer. Preferred polymers are high molecularweight polymers, having a weight average molecular weight (Mw) from10,000 to about 2,500,000, preferably from 20,000 to 500,000, morepreferably from 20,000 to 350,000, and a polydispersity less than 3.5,more preferably less than 3.0, and a Mooney viscosity (ML (1+4) 125° C.)from 1 to 250. More preferably, such polymers have an ethylene contentfrom 65 to 75 percent, a diene content from 0 to 6 percent, and anα-olefin content from 20 to 35 percent.

The ethylene/α-olefin interpolymers can be functionalized byincorporating at least one functional group in its polymer structure.Exemplary functional groups may include, for example, ethylenicallyunsaturated mono- and di-functional carboxylic acids, ethylenicallyunsaturated mono- and di-functional carboxylic acid anhydrides, saltsthereof and esters thereof. Such functional groups may be grafted to anethylene/α-olefin interpolymer, or it may be copolymerized with ethyleneand an optional additional comonomer to form an interpolymer ofethylene, the functional comonomer and optionally other comonomer(s).Means for grafting functional groups onto polyethylene are described forexample in U.S. Pat. Nos. 4,762,890, 4,927,888, and 4,950,541, thedisclosures of these patents are incorporated herein by reference intheir entirety. One particularly useful functional group is malicanhydride.

The amount of the functional group present in the functionalinterpolymer can vary. The functional group can typically be present ina copolymer-type functionalized interpolymer in an amount of at leastabout 1.0 weight percent, preferably at least about 5 weight percent,and more preferably at least about 7 weight percent. The functionalgroup will typically be present in a copolymer-type functionalizedinterpolymer in an amount less than about 40 weight percent, preferablyless than about 30 weight percent, and more preferably less than about25 weight percent.

The amount of the ethylene/α-olefin interpolymer in the polymer blendcompositions disclosed herein can be from about 5 to about 99.5 wt %,from about 9% to about 99.5%, from about 10 to about 90 wt %, from about20 to about 80 wt %, from about 30 to about 70 wt %, from about 10 toabout 50 wt %, from about 50 to about 90 wt %, from about 60 to about 90wt %, or from about 70 to about 90 wt % of the total weight of thepolymer blend.

Second Polymers

As discussed above, the polymer blends provided herein comprise a secondpolymer component. This second polymer component is different than theethylene/α-olefin interpolymer as the first polymer component. Thesecond polymer can be a different ethylene/α-olefin interpolymer, apolyolefin, a polar polymer, an elastomer, and so on. When a secondethylene/α-olefin interpolymer is used, the two ethylene/α-olefininterpolymers in the blend have a different melt index, comonomer type,comonomer content, and/or overall density. The amount of the secondethylene/α-olefin interpolymer in the polymer blend disclosed herein canbe from about 5 to about 99.5 wt %, from about 9% to about 99.5%, fromabout 10 to about 90 wt %, from about 20 to about 80 wt %, from about 30to about 70 wt %, from about 10 to about 50 wt %, from about 50 to about90 wt %, from about 60 to about 90 wt %, or from about 70 to about 90 wt% of the total weight of the polymer blend.

Bimodal physical or in-the-reactor blends of two ethylene/α-olefininterpolymers offer improved combinations of properties (such ascompression set) and processability than a single distributionethylene/α-olefin interpolymers of the same melt index.

Polyolefins

The polymer blends can comprise at least an polyolefin which may improveor modify the properties of the ethylene/α-olefin interpolymer. Thepolyolefin is a polymer derived from one or more olefins. An olefin(i.e., alkene) is a hydrocarbon contains at least one carbon-carbondouble bond. Some non-limiting examples of olefins include linear orbranched, cyclic or acyclic, alkenes having from 2 to about 20 carbonatoms. In some embodiments, the alkene has between 2 and about 10 carbonatoms. In other embodiments, the alkene contains at least twocarbon-carbon double bonds, such as butadiene and 1,5-hexadiene. Infurther embodiments, at least one of the hydrogen atoms of the alkene issubstituted with an alkyl or aryl. In particular embodiments, the alkeneis ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene,4-methyl-1-pentene, norbornene, 1-decene, butadiene, 1,5-hexadiene,styrene or a combination thereof.

Any polyolefin known to a person of ordinary skill in the art may beused to prepare the polymer blend disclosed herein. Non-limitingexamples of polyolefins include polyethylenes (e.g., ultralow, low,linear low, medium, high and ultrahigh density polyethylene);polypropylenes (e.g., low and high density polypropylene); polybutylenes(e.g., polybutene-1); polypentene-1; polyhexene-1; polyoctene-1;polydecene-1; poly-3-methylbutene-1; poly-4-methylpentene-1;polyisoprene; polybutadiene; poly-1,5-hexadiene; interpolymers derivedfrom olefins; interpolymers derived from olefins and other polymers suchas polyvinyl chloride, polystyrene, polyurethane, and the like; andmixtures thereof. In some embodiments, the polyolefin is a homopolymersuch as polyethylene, polypropylene, polybutylene, polypentene-1,poly-3-methylbutene-1, poly-4-methylpentene-1, polyisoprene,polybutadiene, poly-1,5-hexadiene, polyhexene-1, polyoctene-1 andpolydecene-1. In other embodiments, the polyolefin is polypropylene orhigh density polyethylene (HDPE).

In some embodiments, the polyolefin is selected from LDPE, LLDPE, HDPE,EVA, EAA, EMA, ionomers thereof, metallocene LLDPE, impact gradepropylene polymers, random grade propylene polymers, polypropylene and acompbination thereof.

The amount of the polyolefin in the polymer blend can be from about 5 toabout 95 wt %, from about 10 to about 90 wt %, from about 20 to about 80wt %, from about 30 to about 70 wt %, from about 10 to about 50 wt %,from about 50 to about 80 wt %, from about 60 to about 90 wt %, or fromabout 10 to about 30 wt % of the total weight of the polymer blend.

Elastomers

In certain aspects, the polymer blends provided herein comprise at leastone thermoplastic vulcanizates (TPVs), styrenic block copolymers (suchas SBS, SEBS, SEEPS, etc.), neoprene, ENGAGE®, AFFINITY®, Flexomer™,VERSIFY®, VISTAMAXX™, Exact™, Exceed™, functionalized elastomers (MAHg,silane modified, azide modified) polybutadiene rubber, butyl rubber or acombination thereof. The elastomer may present in an amount ranging fromabout 1% to about 95%, about 5 % to about 91%, about 10% to about 80% orabout 20% to about 50% of the total weight of the composition.

Thermoplastic elastomers are rubber-like materials that, unlikeconventional vulcanized rubbers, can be processed and recycled likethermoplastic materials. When the thermoplastic elastomer contains avulcanized rubber, it may also be referred to as a thermoplasticvulcanizate (TPV). TPVs are thermoplastic elastomers with a chemicallycross-linked rubbery phase, produced by dynamic vulcanization. Onemeasure of this rubbery behavior is that the material will retract toless than 1.5 times its original length within one minute, after beingstretched at room temperature to twice its original length and held forone minute before release (ASTM D1566). Another measure is found in ASTMD412, for the determination of tensile set. The materials are alsocharacterized by high elastic recovery, which refers to the proportionof recovery after deformation and may be quantified as percent recoveryafter compression. A perfectly elastic material has a recovery of 100%while a perfectly plastic material has no elastic recovery. Yet anothermeasure is found in ASTM D395, for the determination of compression set.

Thermoplastic vulcanizates containing butyl or halogenated butyl rubberas the rubber phase and a thermoplastic polyolefin as the plastic orresin phase are known in the art. In one aspect, suitable thermoplasticvulcanizates (TPV) are made with polyurethane and chlorosulfonatedpolyethylene or a mixture of chlorosulfonated polyethylene andchlorinated polyethylene by dynamic vulcanization method wherein thevulcanizate contains about 30 to 70% polyurethane and about 70 to 30%chlorosulfonated polyethylene or a mixture of chlorosulfonatedpolyethylene and chlorinated polyethylene wherein the ratio ofchlorosulfonated polyethylene to chlorinated polyethylene is about 3:1to 1:3. Examples of thermoplastic vulcanizates includeethylene-propylene monomer rubber and ethylene-propylene-diene monomerrubber thermoset materials distributed in a crystalline polypropylenematrix.

One example of a commercial TPV is Satoprene® thermoplastic rubber whichis manufactured by Advanced Elastomer Systems and is a mixture ofcrosslinked EPDM particles in a crystalline polypropylene matrix.Another example is VYRAM, consisting of a mixture of polypropylene andnatural rubber, marketed by Advanced Elastomer Systems. Other suitableelastomers include KRATON, a brand of styrene block copolymer (SBC)marketed by Shell, and DYNAFLEX G 6725 (brand), a thermoplasticelastomer marketed by GLS Corporation and which is made with KRATON(brand) polymer.

Styrenic Block Coplymers

In some embodiments, the polymer compositions provided herein compriseat least one block copolymer. Block coplymers include block coplymersthat comprise at least one styrenic block copolymer. The amount of astyrenic block copolymer in the polymer blend can be from about 0.5 toabout 99 wt %, from about 1 to about 95 wt %, from about 10 to about 90wt %, from about 20 to about 80 wt %, from about 30 to about 70 wt %,from about 5 to about 50 wt %, from about 50 to about 95 wt %, fromabout 10 to about 50 wt %, from about 10 to about 30 wt %, or from about50 to about 90 wt % of the total weight of the polymer blend. In someembodiments, the amount of the styrenic block copolymer in the polymerblend can be from about 1 to about 25 wt %, from about 5 to about 15 wt%, from about 7.5 to about 12.5 wt %, or about 10 wt % of the totalweight of the polymer blend.

Generally speaking, styrenic block copolymers include at least twomonoalkenyl arene blocks, preferably two polystyrene blocks, separatedby a block of a saturated conjugated diene, preferably a saturatedpolybutadiene block. The preferred styrenic block copolymers have alinear structure, although branched or radial polymers or functionalizedblock copolymers make useful compounds. The total number averagemolecular weight of the styrenic block copolymer is preferably from30,000 to about 250,000 if the copolymer has a linear structure. Suchblock copolymers may have an average polystyrene content from 10% byweight to 40% by weight.

Suitable unsaturated block copolymers include, but are not limited to,those represented by the following formulas:

A-B-R(-B-A)_(n)  Formula I

or

A_(x)-(BA-)_(y)-BA  Formula II

wherein each A is a polymer block comprising a vinyl aromatic monomer,preferably styrene, and each B is a polymer block comprising aconjugated diene, preferably isoprene or butadiene, and optionally avinyl aromatic monomer, preferably styrene; R is the remnant of amultifunctional coupling agent (if R is present, the block copolymer canbe a star or branched block copolymer); n is an integer from 1 to 5; xis zero or 1; and y is a real number from zero to 4.

Methods for the preparation of such block copolymers are known in theart. See, e.g., U.S. Pat. No. 5,418,290. Suitable catalysts for thepreparation of useful block copolymers with unsaturated rubber monomerunits include lithium based catalysts and especially lithium-alkyls.U.S. Pat. No. 3,595,942 describes suitable methods for hydrogenation ofblock copolymers with unsaturated rubber monomer units to from blockcopolymers with saturated rubber monomer units. The structure of thepolymers is determined by their methods of polymerization. For example,linear polymers result by sequential introduction of the desired rubbermonomer into the reaction vessel when using such initiators aslithium-alkyls or dilithiostilbene and the like, or by coupling a twosegment block copolymer with a difunctional coupling agent. Branchedstructures, on the other hand, may be obtained by the use of suitablecoupling agents having a functionality with respect to the blockcopolymers with unsaturated rubber monomer units of three or more.Coupling may be effected with multifunctional coupling agents such asdihaloalkanes or alkenes and divinyl benzene as well as with certainpolar compounds such as silicon halides, siloxanes or esters ofmonohydric alcohols with carboxylic acids. The presence of any couplingresidues in the polymer may be ignored for an adequate description ofthe block copolymers.

Suitable block copolymers having unsaturated rubber monomer unitsinclude, but are not limited to, styrene-butadiene (SB),styrene-ethylene/butadiene (SEB), styrene-isoprene(SI),styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS),α-methylstyrene-butadiene-α-methylstyrene andα-methylstyrene-isoprene-α-methylstyrene.

The styrenic portion of the block copolymer is preferably a polymer orinterpolymer of styrene and its analogs and homologs includingα-methylstyrene and ring-substituted styrenes, particularlyring-methylated styrenes. The preferred styrenics are styrene andα-methylstyrene, and styrene is particularly preferred.

Block copolymers with unsaturated rubber monomer units may comprisehomopolymers of butadiene or isoprene or they may comprise copolymers ofone or both of these two dienes with a minor amount of styrenic monomer.In some embodiments, the block copolymers are derived from (i) a C₃₋₂₀olefin substituted with an alkyl or aryl group (e.g., 4-methyl-1-penteneand styrene) and (ii) a diene (e.g. butadiene, 1,5-hexadiene,1,7-octadiene and 1,9-decadiene). A non-limiting example of such olefincopolymer includes styrene-butadiene-styrene (SBS) block copolymer.

Preferred block copolymers with saturated rubber monomer units compriseat least one segment of a styrenic unit and at least one segment of anethylene-butene or ethylene-propylene copolymer. Preferred examples ofsuch block copolymers with saturated rubber monomer units includestyrene/ethylene-butene copolymers, styrene/ethylene-propylenecopolymers, styrene/ethylene-butene/styrene (SEBS) copolymers,styrene/ethylene-propylene/styrene (SEPS) copolymers.

Hydrogenation of block copolymers with unsaturated rubber monomer unitsis preferably effected by use of a catalyst comprising the reactionproducts of an aluminum alkyl compound with nickel or cobaltcarboxylates or alkoxides under such conditions as to substantiallycompletely hydrogenate at least 80 percent of the aliphatic double bondswhile hydrogenating no more than 25 percent of the styrenic aromaticdouble bonds. Preferred block copolymers are those where at least 99percent of the aliphatic double bonds are hydrogenated while less than 5percent of the aromatic double bonds are hydrogenated.

The proportion of the styrenic blocks is generally between 8 and 65percent by weight of the total weight of the block copolymer.Preferably, the block copolymers contain from 10 to 35 weight percent ofstyrenic block segments and from 90 to 65 weight percent of rubbermonomer block segments, based on the total weight of the blockcopolymer.

The average molecular weights of the individual blocks may vary withincertain limits. In most instances, the styrenic block segments will havenumber average molecular weights in the range of 5,000 to 125,000,preferably from 7,000 to 60,000 while the rubber monomer block segmentswill have average molecular weights in the range of 10,000 to 300,000,preferably from 30,000 to 150,000. The total average molecular weight ofthe block copolymer is typically in the range of 25,000 to 250,000,preferably from 35,000 to 200,000.

Further, the various block copolymers suitable for use in embodiments ofthe invention may be modified by graft incorporation of minor amounts offunctional groups, such as, for example, maleic anhydride by any of themethods well known in the art.

Suitable block copolymers include, but are not limited to, thosecommercially available, such as, KRATON™ supplied by KRATON Polymers LLCin Houston, Tex., and VECTOR™ supplied by Dexco Polymers, L.P. inHouston, Tex.

Polar polymers

In some embodiments, the polymer compositions provided herein compriseat least one polar polymer. A polar polymer is intended to denotethermoplastic, elastomeric and heat-curable polymers resulting frompolymerization by polyaddition or polycondensation, which have apermanent dipole moment or, in other words, which contain dipolar groupsin their molecule. By way of examples of such polar polymers there maybe mentioned halogenated polymers such as vinyl chloride, vinylidenechloride and vinyl bromide polymers (homo- and copolymers), polymerscontaining nitrile functional groups, such as polyacrylonitrile andacrylonitrile/styrene copolymers or acrylonitrile/butadiene/styrene(ABS) copolymers, cellulose-based polymers, polyketones, both aliphaticand aromatic polyesters such as polymethyl or polyethyl acrylates andmethacrylates and polyethylene terephthalate, vinyl alcohol/ethylenecopolymers (that is o say vinyl acetate/ethylene copolymers in which atleast 90% of the acetate groups have been converted into hydroxyl groupsby hydrolysis or alcoholysis), aromatic polycarbonates, polyamides ornylons, and polyurethanes which, furthermore, are all well-knownpolymers. In some embodiments, polar polymers are nylon, polyamide,ethylene vinyl acetate, polyvinyl chloride,acrylonitrile/butadiene/styrene (ABS) copolymers, aromaticpolycarbonates, ethylene/carboxylic acid copolymers or acrylics. Thepolar polymer may be present in a range from about 0.25% to about 90%,1% to about 80%, 10% to about 50% or 10% to about 40% by total weight ofthe blend.

In certain embodiments, the polar polymer in the polymer blendcompositions is an olefin/carboxylic acid interpolymer. Suitablecarboxylic acid monomers include ethylenically unsaturated carboxylicacid monomers that have three to eight carbon atoms per molecule,including anhydrides, alkyl esters, half esters, etc. Examples ofethylenically unsaturated carboxylic acids include, but are not limitedto, acrylic acid, methacrylic acid, maleic acid and anhydride, itaconicacid, fumaric acid, crotonic acid, citraconic acid and anhydride, methylhydrogen maleate, ethyl hydrogen maleate, etc. In addition, otherethylenically unsaturated monomers which are not entirely hydrocarbonmay also be used to make the interpolymers. Examples of such monomersinclude, but are not limited to, esters of ethylenically unsaturatedcarboxylic acid, such as ethyl acrylate, methyl methacrylate, ethylmethacrylate, methyl acrylate, isobutyl acrylate, and methyl fumarate.They may also include unsaturated esters of non-polymerizable carboxylicacid, such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinylhalides, such as vinyl and vinylidene chloride, vinyl esters,ethylenically unsaturated amides and nitriles, such as acrylamide,acrylonitrile, methacrylonitrile, and fumaronitrile.

The olefin monomers should be present in the interpolymer in an amountfrom about 60 percent to about 90 percent by weight. The ethylenicallyunsaturated carboxylic acid monomers should be present in theinterpolymer from about 5 percent to about 25 percent by weight. Anothertype of ethylenically unsaturated carboxylic acid monomers may bepresent from 0 to about 20 wt. percent in the interpolymer. Theaforementioned interpolymers may be prepared by the methods andprocedures as described in U.S. Pat. No. 3,436,363; U.S. Pat. No.3,520,861; U.S. Pat. No. 4,599,392; and U.S. Pat. No. 4,988,781. Thedisclosures of these patents are incorporated by reference herein intheir entirety. One skilled in the art recognizes that thecharacteristics of such polymers may be tailored by adjusting variousparameters, such are reaction time, temperature and pressure, of apolymerization method or procedure. One parameter that may be adjustedto control the melt index of a polymer is the hydrogen concentration.Higher hydrogen concentrations tend to produce polymers with higher meltindices, although the relationship is not necessarily linear.

Suitable interpolymers can also be made from preformed, non-acidpolymers by subsequent chemical reactions carried out thereon. Forexample, the carboxylic acid group may be supplied by grafting a monomersuch as acrylic acid or maleic acid onto a polymer substrate such asethylene. Additionally, interpolymers containing carboxylic anhydride,ester, amide, acylhalide, and nitrile groups can be hydrolyzed tocarboxylic acid groups.

Furthermore, the interpolymers may be further modified by the methoddescribed in U.S. Pat. No. 5,384,373, which is incorporated by referenceherein in its entirety. The resulting modified interpolymer may also beused in embodiments of the invention. α-methyl styrene, toluene, t-butylstyrene, etc. Suitable ethylenically unsaturated carboxylic acidmonomers preferably have three to eight carbon atoms per molecule,including anhydrides, alkyl esters, half esters, etc. Examples ofethylenically unsaturated carboxylic acids include, but are not limitedto, acrylic acid, methacrylic acid, maleic acid and anhydride, itaconicacid, fumaric acid, crotonic acid, citraconic acid and anhydride, methylhydrogen maleate, ethyl hydrogen maleate, etc. In addition, otherethylenically unsaturated monomers which are not entirely hydrocarbonmay also be used to make the interpolymers. Examples of such monomersinclude, but are not limited to, esters of ethylenically unsaturatedcarboxylic acid, such as ethyl acrylate, methyl methacrylate, ethylmethacrylate, methyl acrylate, isobutyl acrylate, and methyl fumarate.They may also include unsaturated esters of non-polymerizable carboxylicacid, such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinylhalides, such as vinyl and vinylidene chloride, vinyl esters,ethylenically unsaturated amides and nitriles, such as acrylamide,acrylonitrile, methacrylonitrile, and fumaronitrile.

Certain exemplary olefin/carboxylic acid interpolymers includeethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers,ethylene-itaconic acid copolymers, ethylene-methyl hydrogen maleatecopolymers, ethylene-maleic acid copolymers, ethylene-acrylic acidcopolymers, ethylene-methacrylate copolymers, ethylene-methacrylicacid-ethacrylate copolymers, ethylene-itaconic acid-methacrylatecopolymers, ethylene-itaconic acid-methacrylate copolymers,ethylene-methyl hydrogen maleate-ethyl acrylate copolymers,ethylene-methacrylic acid-vinyl acetate copolymers, ethylene-acrylicacid copolymers, ethylene-acrylic acid-vinyl alcohol copolymers,ethylene-acrylic acid-carbon monoxide copolymers,ethylene-propylene-acrylic acid copolymers, ethylene-methacrylicacid-acrylonitrile copolymers, ethylene-fumaric acid-vinyl methyl ethercopolymers, ethylene-vinyl chloride-acrylic acid copolymers,ethylene-vinylidene chloride-acrylic acid copolymers,ethylene-vinylidene chloride-acrylic acid copolymers, ethylene-vinylfluoride-methacrylic acid copolymers andethylene-chlorotrifluoroethlyene-methacrylic acid copolymers.

The ionomers of olefin/carboxylic acid interpolymers are ionicallycrosslinked to thermoplastics generally obtained by neutralizing acopolymer containing pendant acid groups e.g., carboxylic acid groups,with an ionizable metal compound, e.g., a compound of the monovalent,divalent and/or trivalent metals of Group I, II, IV-A and VIIIB of theperiodic table of the elements.

Preferred groups of ionomer resins are derived from a copolymer of atleast one alpha-olefin and at least one ethylenically unsaturatedcarboxylic acid and/or anhydride. Suitable alpha-olefins includeethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene,3-methylbutene, isobutene, butadiene, isoprene, α-methyl styrene,toluene, t-butyl styrene and styrene and the like. Suitable carboxylicacids and anhydrides include acrylic acid, methacrylic acid, ethacrylicacid, maleic acid, fumaric acid, maleic anhydride, and the like. Theforegoing copolymers generally contain from about 0.2 to about 20 molepercent, and preferably from about 0.5 to about 10 mole percent,carboxylic acid groups.

Preferred ionomers are obtained by reacting the foregoing copolymerswith a sufficient amount of metal ions as to neutralize at least someportion of the acid groups, preferably at least about 5 percent byweight and preferably from about 20 to about 100 percent by weight, ofthe acid groups present. Suitable metal ions include Na⁺, K⁺, Li⁺, Cs⁺,Rb⁺, Hg⁺, Cu⁺, Be⁺², Mg⁺², Ca⁺², Sr⁺², Cu⁺², Cd⁺², Hg⁺², Sn⁺², Pb⁺²,Fe⁺², Co⁺², Ni⁺², Zn⁺², Al⁺³ and Y⁺³. Preferred metals suitable forneutralizing the copolymers used herein are the alkali metals,particularly, cations such as sodium, lithium and potassium and alkalineearth metals, in particular, cations such as calcium, magnesium andzinc. One or more ionomers may be used in the present invention.Preferred ionomers include Surlyn™ 1702, which is a zinc salt of anethylene and methacrylic acid copolymer and Surlyn™ 8660, which is asodium salt of an ethylene and methacrylic acid copolymer. Both Surlyn™1702 and Surlyn™ 8660 may be obtained from E.I. Dupont de Nemours &Company, Wilmington, Del.

The ethylene/carboxylic acid interpolymer or ionomer may be found in thegasket composition in the range from about 2% to about 15% by weight ofthe three component composition. Preferably, the ethylene/carboxylicacid interpolymer or ionomer may be found in the gasket composition inthe range from about 4% to about 12%, about 2% to about 12% by weight,or from about 2% to about 10%. Most preferably, the ethylene/carboxylicacid interpolymer or ionomer may be found in the gasket composition inan amount in the range from about 4% to about 10%. The melt index of theinterpolymer of ethylene and acrylic acid is about 0.15 to about 400g/10 min. Preferably, the melt index is about 1 to about 100 g/10 min.,and most preferably, from about 1 to about 30 g/10 min.

In another embodiment of the invention, a gasket composition maycomprise ethylene/alpha-olefin polymers used in the present inventionand a interpolymer of ethylene and acrylic acid. The acrylic acid can befound in the interpolymer in the range from about 3% to about 50% byweight of the interpolymer. Preferably, the acrylic acid can be found inthe range from about 5% to 18%, and most preferably, from about 6.5% toabout 15%.

An example of a suitable interpolymer of ethylene and acrylic acid isPrimacor™ 5980 (having about 20% acrylic acid and a melt index (I₂) ofabout 300 grams/10 minutes), which may be purchased from The DowChemical Company. Examples of other suitable interpolymers of ethyleneand acrylic acid may be found in U.S. Pat. Nos. 4,500,664, 4,988,781 and4,599,392, the disclosures of which are hereby incorporated byreference.

Additives

Optionally, the polymer blends disclosed herein can comprise at leastone additive for the purposes of improving and/or controlling theprocessibility, appearance, physical, chemical, and/or mechanicalproperties of the polymer blends. In some embodiments, the polymerblends do not comprise an additive. Any plastics additive known to aperson of ordinary skill in the art may be used in the polymer blendsdisclosed herein. Non-limiting examples of suitable additives includeslip agents, anti-blocking agents, plasticizers, antioxidants, UVstabilizers, colorants or pigments, fillers, lubricants, antifoggingagents, flow aids, coupling agents, cross-linking agents, nucleatingagents, surfactants, solvents, flame retardants, antistatic agents, oilor extender, odor absorber and combinations thereof. The total amount ofthe additives can range from about greater than 0 to about 80%, fromabout 0.001% to about 70%, from about 0.01% to about 60%, from about0.1% to about 50%, from about 1% to about 40%, or from about 10% toabout 50% of the total weight of the polymer blend. Some polymeradditives have been described in Zweifel Hans et al., “PlasticsAdditives Handbook,” Hanser Gardner Publications, Cincinnati, Ohio, 5thedition (2001), which is incorporated herein by reference in itsentirety.

Slip Agents

In some embodiments, the polymer blends disclosed herein comprise a slipagent. In other embodiments, the polymer blends disclosed herein do notcomprise a slip agent. Slip is the sliding of film surfaces over eachother or over some other substrates. The slip performance of films canbe measured by ASTM D 1894, Static and Kinetic Coefficients of Frictionof Plastic Film and Sheeting, which is incorporated herein by reference.In general, the slip agent can convey slip properties by modifying thesurface properties of films; and reducing the friction between layers ofthe films and between the films and other surfaces with which they comeinto contact. In some embodiments, the slip agents include suitableabrasion resistance enhancing additives as would be known to the skilledartisan.

Any slip agent known to a person of ordinary skill in the art may beadded to the polymer blends disclosed herein. In some embodiments, theslip agent is hydrocarbon having one or more functional groups selectedfrom hydroxide, aryls and substituted aryls, halogens, alkoxys,carboxylates, esters, carbon unsaturation, acrylates, oxygen, nitrogen,carboxyl, sulfate and phosphate. In some embodiments, the slip agent isselected from esters, amides, alcohols and acids of aromatic andaliphatic hydrocarbon oils. In another embodiment, the slip agent iscarnauba wax, microcrystalline wax or polyolefin waxes or any otherconventional wax. Amounts of wax range from about 2 to about 15 weight %based on the total weight of the composition. Any conventional waxuseful in thermoplastic films may be contemplated. In some embodiments,the slip agent is a fluoro-containing polymer. In some embodiments, theslip agent is an oxidized polyethylene.

In some embodiments, the slip agents are silicon based materials such ashigh molecular weight polydialkyl siloxanes such as polydimethylsiloxanes, silicone oil or gum additive; waxy materials that bloom tothe surface such as erucamide, and some specialty materials that containa combination of a hard tough plastic such as nylon with surface activeagents. In some embodiments, the amount of polydialkylsiloxane issufficient to reduce friction when the film may be formed or when it maybe manipulated in packaging machinery.

In a particular embodiment, the slip agent for the polymer blendsdisclosed herein is an amide represented by Formula (I) below:

wherein each of R¹ and R² is independently H, alkyl, cycloalkyl,alkenyl, cycloalkenyl or aryl; and R³ is alkyl or alkenyl, each havingabout 11 to about 39 carbon atoms, about 13 to about 37 carbon atoms,about 15 to about 35 carbon atoms, about 17 to about 33 carbon atoms orabout 19 to about 33 carbon atoms. In some embodiments, R³ is alkyl oralkenyl, each having at least 19 to about 39 carbon atoms. In otherembodiments, R³ is pentadecyl, heptadecyl, nonadecyl, heneicosanyl,tricosanyl, pentacosanyl, heptacosanyl, nonacosanyl, hentriacontanyl,tritriacontanyl, nonatriacontanyl or a combination thereof. In furtherembodiments, R³ is pentadecenyl, heptadecenyl, nonadecenyl,heneicosanenyl, tricosanenyl, pentacosanenyl, heptacosanenyl,nonacosanenyl, hentriacontanenyl, tritriacontanenyl, nonatriacontanenylor a combination thereof.

In a further embodiment, the slip agent for the polymer blends disclosedherein is an amide represented by Formula (II) below:

CH₃—(CH₂)_(m)—(CH═CH)_(p)—(CH₂)_(n)—C(═O)—NR¹R²  (II)

wherein each of m and n is independently an integer between about 1 andabout 37; p is an integer between 0 and 3; each of R¹ and R² isindependently H, alkyl, cycloalkyl, alkenyl, cycloalkenyl or aryl; andthe sum of m, n and p is at least 8. In some embodiments, each of R¹ andR² of Formulae (I) and (II) is an alkyl group containing between 1 andabout 40 carbon atoms or an alkenyl group containing between 2 and about40 carbon atoms. In further embodiments, each of R¹ and R² of Formulae(I) and (II) is H. In certain embodiments, the sum of m, n and p is atleast 18.

The amide of Formula (I) or (II) can be prepared by the reaction of anamine of formula H—NR¹R² where each of R¹ and R² is independently H,alkyl, cycloalkyl, alkenyl, cycloalkenyl or aryl with a carboxylic acidhaving a formula of R³—CO₂H or CH₃—(CH₂)_(m)—(CH═CH)_(p)—(CH₂)_(n)—CO₂Hwhere R³ is alkyl or alkenyl, each having at least 19 to about 39 carbonatoms; each of m and n is independently an integer between about 1 andabout 37; and p is 0 or 1. The amine of formula H—NR¹R² can be ammonia(i.e., each of R¹ and R² is H), a primary amine (i.e., R¹ is alkyl,cycloalkyl, alkenyl, cycloalkenyl or aryl and R² is H) or a secondaryamine (i.e., each of R¹ and R² is independently alkyl, cycloalkyl,alkenyl, cycloalkenyl or aryl). Some non-limiting examples of primaryamine include methylamine, ethylamine, octadecylamine, behenylamine,tetracosanylamine, hexacosanylamine, octacosanylamine, triacontylamine,dotriacontylamine, tetratriacontylamine, tetracontylamine,cyclohexylamine and combinations thereof. Some non-limiting examples ofsecondary amine include dimethylamine, diethylamine, dihexadecylamine,dioctadecylamine, dieicosylamine, didocosylamine, dicetylamine,distearylamine, diarachidylamine, dibehenylamine, dihydrogenated tallowamine, and combinations thereof. The primary amines and secondary aminescan be prepared by methods known to a person of ordinary skill in theart or obtained from a commercial supplier such as Aldrich Chemicals,Milwaukee, Wis.; ICC Chemical Corporation, New York, N.Y.; Chemos GmbH,Regenstauf, Germany; ABCR GmbH & Co. KG, Karlsruhe, Germany; and AcrosOrganics, Geel, Belgium.

The primary amines or secondary amines may be prepared by reductiveamination reaction. The reductive amination is the process by whichammonia or a primary amine is condensed with an aldehyde or a ketone toform the corresponding imine which is subsequently reduced to an amine.The subsequent reduction of imine to amine may be accomplished byreacting the imine with hydrogen and a suitable hydrogenation catalystsuch as Raney Nickel and platinum oxide, aluminum-mercury amalgam, or ahydride such as lithium aluminum hydride, sodium cyanoborohydride, andsodium borohydride. The reductive amination is described in U.S. Pat.No. 3,187,047; and articles by Haskelberg, “Aminative Reduction ofKetones,” J. Am. Chem. Soc., 70 (1948) 2811-2; Mastagli et al., “Studyof the Aminolysis of Some Ketones and Aldehydes,” Bull. soc. chim.France (1950) 1045-8; B. J. Hazzard, Practical Handbook of OrganicChemistry, Addison-Wesley Publishing Co., Inc., pp. 458-9 and 686(1973); and Alexander et al., “A Low Pressure Reductive AlkylationMethod for the Conversion of Ketones to Primary Amines,” J. Am. Chem.Soc., 70, 1315-6 (1948). The above U.S. patent and articles areincorporated herein by reference.

Non-limiting examples of the carboxylic acid include straight-chainsaturated fatty acids such as tetradecanoic acid, pentadecanoic acid,hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoicacid, eicosanoic acid, heneicosanic acid, docosanoic acid, tricosanoicacid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid,heptacosanoic acid, octacosanoic acid, nonacosanoic acid, triacontanoicacid, hentriacontanoic acid, dotriacontanoic acid, tetratriacontanoicacid, hexatriacontanoic acid, octatriacontanoic acid and tetracontanoicacid; branched-chain saturated fatty acids such as16-methylheptadecanoic acid, 3-methyl-2-octylynonanoic acid,2,3-dimethyloctadecanoic acid, 2-methyltetracosanoic acid,11-methyltetracosanoic acid, 2-pentadecyl-heptadecanoic acid;unsaturated fatty acids such as trans-3-octadecenoic acid,trans-11-eicosenoic acid, 2-methyl-2-eicosenoic acid,2-methyl-2-hexacosenoic acid, β-eleostearic acid, α-parinaric acid,9-nonadecenoic acid, and 22-tricosenoic acid, oleic acid and erucicacid. The carboxylic acids can be prepared by methods known to a personof ordinary skill in the art or obtained from a commercial supplier suchas Aldrich Chemicals, Milwaukee, Wis.; ICC Chemical Corporation, NewYork, N.Y.; Chemos GmbH, Regenstauf, Germany; ABCR GmbH & Co. KG,Karlsruhe, Germany; and Acros Organics, Geel, Belgium. Some knownmethods for the preparation of the carboxylic acids include theoxidation of the corresponding primary alcohols with an oxidation agentsuch as metal chromates, metal dichromates and potassium permanganate.The oxidation of alcohols to carboxylic acids is described in Carey etal., “Advance Organic Chemistry, Part B: Reactions and Synthesis,”Plenum Press, New York, 2nd Edition, pages 481-491 (1983), which isincorporated herein by reference.

The amidation reaction can take place in a solvent that is not reactivetoward the carboxylic acid. Non-limiting examples of suitable solventsinclude ethers (i.e., diethyl ether and tetrahydrofuran), ketones (suchas acetone and methyl ethyl ketone), acetonitrile, dimethyl sulfoxide,dimethyl formamide and the like. The amidation reaction can be promotedby a base catalyst. Non-limiting examples of the base catalyst includeinorganic bases such as sodium hydroxide, potassium hydroxide, sodiumcarbonate, potassium carbonate, sodium hydrogen carbonate, sodiumacetate, ammonium acetate, and the like, metal alkoxides such as sodiummethoxide, sodium ethoxide, and the like, amines such as triethylamine,diisopropylethylamine, and the like. In some embodiments, the catalystis an amine or a metal alkoxide.

In some embodiments, the slip agent is a primary amide with a saturatedaliphatic group having about 12 to about 40 carbon atoms or about 18 toabout 40 carbon atoms (e.g., stearamide and behenamide). In otherembodiments, the slip agent is a primary amide with an unsaturatedaliphatic group containing at least one carbon-carbon double bond andbetween 18 and about 40 carbon atoms (e.g., erucamide and oleamide). Infurther embodiments, the slip agent is a primary amide having at least20 carbon atoms. In some embodiments, the slip agents are secondaryamides having about 18 to about 80 carbon atoms (e.g., stearylerucamide, behenyl erucamide, methyl erucamide and ethyl erucamide);secondary-bis-amides having about 18 to about 80 carbon atoms (e.g.,ethylene-bis-stearamide and ethylene-bis-oleamide); and combinationsthereof. In further embodiments, the slip agent is erucamide, oleamide,stearamide, behenamide, ethylene-bis-stearamide, ethylene-bis-oleamide,stearyl erucamide, behenyl erucamide, erucyl erucamide, oleylpalimitamide, stearyl stearamide, erucyl stearamide, ethylene bisamidessuch as N,N-ethylenebisstearamide, N,N-ethylenebisolamide and the like,13-cis-docosenamide or a combination thereof. In a particularembodiment, the slip agent is erucamide. In further embodiments, theslip agent is commercially available having a trade name such as ATMER™SA from Uniqema, Everberg, Belgium; ARMOSLIP® from Akzo Nobel PolymerChemicals, Chicago, Ill.; KEMAMIDE® from Witco, Greenwich, Conn.; andCRODAMIDE® from Croda, Edison, N.J. Where used, the amount of the slipagent in the polymer blend can be from about greater than 0 to about 10wt %, about greater than 0 to about 8 wt %, about greater than 0 toabout 3 wt %, from about 0.0001 to about 2 wt %, from about 0.001 toabout 1 wt %, from about 0.001 to about 0.5 wt % or from about 0.05 toabout 0.25 wt % of the total weight of the polymer blend. Some slipagents have been described in Zweifel Hans et al., “Plastics AdditivesHandbook,” Hanser Gardner Publications, Cincinnati, Ohio, 5th edition,Chapter 8, pages 601-608 (2001), which is incorporated herein byreference.

Anti-Blocking Agents

Optionally, the polymer blends disclosed herein can comprise ananti-blocking agent. In some embodiments, the polymer blends disclosedherein do not comprise an anti-blocking agent. The anti-blocking agentcan be used to prevent the undesirable adhesion between touching layersof articles made from the polymer blends, particularly under moderatepressure and heat during storage, manufacture or use. Any anti-blockingagent known to a person of ordinary skill in the art may be added to thepolymer blends disclosed herein. Non-limiting examples of anti-blockingagents include minerals (e.g., clays, chalk, and calcium carbonate),synthetic silica gel (e.g., SYLOBLOC® from Grace Davison, Columbia,Md.), natural silica (e.g., SUPER FLOSS® from Celite Corporation, SantaBarbara, Calif.), talc (e.g., OPTIBLOC® from Luzenac, Centennial,Colo.), zeolites (e.g., SIPERNAT® from Degussa, Parsippany, N.J.),aluminosilicates (e.g., SILTON® from Mizusawa Industrial Chemicals,Tokyo, Japan), limestone (e.g., CARBOREX® from Omya, Atlanta, Ga.),spherical polymeric particles (e.g., EPOSTAR®, poly(methyl methacrylate)particles from Nippon Shokubai, Tokyo, Japan and TOSPEARL®, siliconeparticles from GE Silicones, Wilton, Conn.), waxes, amides (e.g.erucamide, oleamide, stearamide, behenamide, ethylene-bis-stearamide,ethylene-bis-oleamide, stearyl erucamide and other slip agents),molecular sieves, and combinations thereof. The mineral particles canlower blocking by creating a physical gap between articles, while theorganic anti-blocking agents can migrate to the surface to limit surfaceadhesion.

Where used, the amount of the anti-blocking agent in the polymer blendcan be from about greater than 0 to about 3 wt %, from about 0.0001 toabout 2 wt %, from about 0.001 to about 1 wt %, or from about 0.001 toabout 0.5 wt % of the total weight of the polymer blend. Someanti-blocking agents have been described in Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 7, pages 585-600 (2001), which isincorporated herein by reference.

Plasticizers

Optionally, the polymer blends disclosed herein can comprise aplasticizer or plasticizing oil or an extender oil. In general, aplasticizer is a chemical that can increase the flexibility and lowerthe glass transition temperature of polymers. Any plasticizer known to aperson of ordinary skill in the art may be added to the polymer blendsdisclosed herein. Non-limiting examples of plasticizers includeabietates, adipates, alkyl sulfonates, azelates, benzoates, chlorinatedparaffins, citrates, epoxides, glycol ethers and their esters,glutarates, hydrocarbon oils, isobutyrates, oleates, pentaerythritolderivatives, phosphates, phthalates, esters, polybutenes, ricinoleates,sebacates, sulfonamides, tri- and pyromellitates, biphenyl derivatives,stearates, difuran diesters, fluorine-containing plasticizers,hydroxybenzoic acid esters, isocyanate adducts, multi-ring aromaticcompounds, natural product derivatives, nitriles, siloxane-basedplasticizers, tar-based products, thioeters and combinations thereof.

In further embodiments, the plasticizers include olefin oligomers, lowmolecular weight polyolefins such as liquid polybutene, phthalates,mineral oils such as naphthenic, paraffinic, or hydrogenated (white)oils (e.g. Kaydol oil), vegetable and animal oil and their derivatives,petroleum derived oils, and combinations thereof. In some embodiments,the plasticizers include polypropylene, polybutene, hydrogenatedpolyisoprene, hydrogenated polybutadiene, polypiperylene and copolymersof piperylene and isoprene, and the like having average molecularweights between about 350 and about 10,000. In other embodiments, theplasticizers include glyceryl esters of the usual fatty acids andpolymerization products thereof.

In some embodiments, a suitable insoluble plasticizer may be selectedfrom the group which includes dipropylene glycol dibenzoate,pentaerythritol tetrabenzoate; polyethylene glycol400-di-2-ethylhexoate; 2-ethylhexyl diphenyl phsophate; butyl benzylphthalate, dibutyl phthalate, dioctyl phthalate, various substitutedcitrates, and glycerates. Suitable dipropylene glycol dibenzoate andpentaerythritol tetrabenzoate may be purchased from Velsicol ChemicalCompany of Chicago, Ill. under the trade designations “Benzoflex 9-88and S-552”, respectively. Further, a suitable polyethylene glycol400-di-2-ethylhexoate may be purchased from C.P. Hall Company ofChicago, Ill. under the trade designation “Tegmer 809”. A suitable2-ethylhexyl diphenyl phosphate, and a butyl benzyl phthalate may bepurchased from Monsanto Industrial Chemical Company of St. Louis, Mo.under the trade designation “Santicizer 141 and 160”, respectively. Insome embodiments, AFFINITY® GA high flow polymers, such as AFFINITY® GA1950 POP and AFFINITY® GA 1900 POP as extenders to improveprocessability without noticeably reducing key performance properties.

Some plasticizers have been described in George Wypych, “Handbook ofPlasticizers,” ChemTec Publishing, Toronto-Scarborough, Ontario (2004),which is incorporated herein by reference. Where used, the amount of theplasticizer in the polymer blend can be from greater than 0 to about 65wt %, greater than 0 to about 50 wt %, greater than 0 to about 25 wt %,greater than 0 to about 15 wt %, from about 0.5 to about 10 wt %, orfrom about 1 to about 5 wt % of the total weight of the polymer blend.

Tackifiers

In some embodiments, the compositions disclosed herein can comprise atackifier or tackifying resin or tackifier resin. The tackifier maymodify the properties of the composition such as viscoelastic properties(e.g., tan delta), rheological properties (e.g., viscosity), tackiness(i.e., ability to stick), pressure sensitivity, and wetting property. Insome embodiments, the tackifier is used to improve the tackiness of thecomposition. In other embodiments, the tackifier is used to reduce theviscosity of the composition. In further embodiments, the tackifier isused to render the composition a pressure-sensitive adhesive. Inparticular embodiments, the tackifier is used to wet out adherentsurfaces and/or improve the adhesion to the adherent surfaces.

Any tackifier known to a person of ordinary skill in the art may be usedin the adhesion composition disclosed herein. Tackifiers suitable forthe compositions disclosed herein can be solids, semi-solids, or liquidsat room temperature. Non-limiting examples of tackifiers include (1)natural and modified rosins (e.g., gum rosin, wood rosin, tall oilrosin, distilled rosin, hydrogenated rosin, dimerized rosin, andpolymerized rosin); (2) glycerol and pentaerythritol esters of naturaland modified rosins (e.g., the glycerol ester of pale, wood rosin, theglycerol ester of hydrogenated rosin, the glycerol ester of polymerizedrosin, the pentaerythritol ester of hydrogenated rosin, and thephenolic-modified pentaerythritol ester of rosin); (3) copolymers andterpolymers of natured terpenes (e.g., styrene/terpene and alpha methylstyrene/terpene); (4) polyterpene resins and hydrogenated polyterpeneresins; (5) phenolic modified terpene resins and hydrogenatedderivatives thereof (e.g., the resin product resulting from thecondensation, in an acidic medium, of a bicyclic terpene and a phenol);(6) aliphatic or cycloaliphatic hydrocarbon resins and the hydrogenatedderivatives thereof (e.g., resins resulting from the polymerization ofmonomers consisting primarily of olefins and diolefins); (7) aromatichydrocarbon resins and the hydrogenated derivatives thereof; (8)aromatic modified aliphatic or cycloaliphatic hydrocarbon resins and thehydrogenated derivatives thereof; and combinations thereof. The amountof the tackifier in the composition can be from about 5 to about 70 wt%, from about 10 to about 65 wt %, or from about 15 to about 60 wt % ofthe total weight of the composition.

In other embodiments, the tackifiers include rosin-based tackifiers(e.g. AQUATAC® 9027, AQUATAC® 4188, SYLVALITE®, SYLVATAC® and SYLVAGUM®rosin esters from Arizona Chemical, Jacksonville, Fla.). In otherembodiments, the tackifiers include polyterpenes or terpene resins(e.g., SYLVARES® terpene resins from Arizona Chemical, Jacksonville,Fla.). In other embodiments, the tackifiers include aliphatichydrocarbon resins such as resins resulting from the polymerization ofmonomers consisting of olefins and diolefins (e.g., ESCOREZ® 1310LC,ESCOREZ® 2596 from ExxonMobil Chemical Company, Houston, Tex.) and thehydrogenated derivatives thereof; alicyclic petroleum hydrocarbon resinsand the hydrogenated derivatives thereof (e.g. ESCOREZ® 5300 and 5400series from Exxonmobil Chemical Company; EASTOTAC® resins from EastmanChemical, Kingsport, Tenn.). In further embodiments, the tackifiers aremodified with tackifier modifiers including aromatic compounds (e.g.,ESCOREZ® 2596 from ExxonMobil Chemical Company) and low softening pointresins (e.g., AQUATAC 5527 from Arizona Chemical, Jacksonville, Fla.).In some embodiments, the tackifier is an aliphatic hydrocarbon resinhaving at least five carbon atoms. In other embodiments, the tackifierhas a Ring and Ball (R&B) softening point equal to or greater than 80°C. The Ring and Ball (R&B) softening point can be measured by the methoddescribed in ASTM E28.

In some embodiments, the performance characteristics of the tackifier inthe composition disclosed herein can be directly related to itscompatibility with the ethylene/α-olefin interpolymer. Preferably, thecompositions with desirable adhesive properties can be obtained withtackifiers that are compatible with the interpolymer. For example, whena compatible tackifier is added in the correct concentration to theinterpolymer, desirable tack properties can be produced. Althoughincompatible tackifiers may not produce desirable tack properties, theymay be used to impact other desirable properties. For example, theproperties of the composition can be fine-tuned by the addition of atackifier having limited compatibility to reduce the tack level and/orincrease the cohesive strength characteristics.

Antioxidants

In some embodiments, the polymer blends disclosed herein optionallycomprise an antioxidant that can prevent the oxidation of polymercomponents and organic additives in the polymer blends. Any antioxidantknown to a person of ordinary skill in the art may be added to thepolymer blends disclosed herein. Non-limiting examples of suitableantioxidants include aromatic or hindered amines such as alkyldiphenylamines, phenyl-α-naphthylamine, alkyl or aralkyl substitutedphenyl-α-naphthylamine, alkylated p-phenylene diamines,tetramethyl-diaminodiphenylamine and the like; phenols such as2,6-di-t-butyl-4-methylphenol;1,3,5-trimethyl-2,4,6-tris(3′,5′-di-t-butyl-4′-hydroxybenzyl)benzene;tetrakis[(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane(e.g., IRGANOX™ 1010, from Ciba Geigy, New York); acryloyl modifiedphenols; octadecyl-3,5-di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX™1076, commercially available from Ciba Geigy); phosphites andphosphonites; hydroxylamines; benzofuranone derivatives; andcombinations thereof. Where used, the amount of the antioxidant in thepolymer blend can be from about greater than 0 to about 5 wt %, fromabout 0.0001 to about 2.5 wt %, from about 0.001 to about 1 wt %, orfrom about 0.001 to about 0.5 wt % of the total weight of the polymerblend. Some antioxidants have been described in Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 1, pages 1-140 (2001), which is incorporatedherein by reference.

UV Stabilizers

In other embodiments, the polymer blends disclosed herein optionallycomprise an UV stabilizer that may prevent or reduce the degradation ofthe polymer blends by UV radiations. Any UV stabilizer known to a personof ordinary skill in the art may be added to the polymer blendsdisclosed herein. Non-limiting examples of suitable UV stabilizersinclude benzophenones, benzotriazoles, aryl esters, oxanilides, acrylicesters, formamidines, carbon black, hindered amines, nickel quenchers,hindered amines, phenolic antioxidants, metallic salts, zinc compoundsand combinations thereof. Where used, the amount of the UV stabilizer inthe polymer blend can be from about greater than 0 to about 5 wt %, fromabout 0.01 to about 3 wt %, from about 0.1 to about 2 wt %, or fromabout 0.1 to about 1 wt % of the total weight of the polymer blend. SomeUV stabilizers have been described in Zweifel Hans et al., “PlasticsAdditives Handbook,” Hanser Gardner Publications, Cincinnati, Ohio, 5thedition, Chapter 2, pages 141-426 (2001), which is incorporated hereinby reference.

Barrier Resins

Barrier resins are resins of all types which protects infiltration ofcontaminants, exfiltration of flavor, color, odor, etc., as well aspreservation of the contents of an article made from the polymers blendsprovided herein. Exemplary barrier resins include, but are not limitedto EVOH, PVDC, Nylon, PET, PP, PCTFE, COC, LCP, nitrile (AN-MA)copolymers, thermoplastic polyesters, tie layer resins, andvapor-permeable resins, and combinations thereof. The amount of barrierresin in the polymer blend can range from greater than 0% to about 10%,about 0.001% to about 10%, about 0.1% to about 8% or about 1% to about5% of the total weight of the composition.

Pigments

In further embodiments, the polymer blends disclosed herein optionallycomprise a colorant or pigment that can change the look of the polymerblends to human eyes. Any colorant or pigment known to a person ofordinary skill in the art may be added to the polymer blends disclosedherein. Non-limiting examples of suitable colorants or pigments includeinorganic pigments such as metal oxides such as iron oxide, zinc oxide,and titanium dioxide, mixed metal oxides, carbon black, organic pigmentssuch as anthraquinones, anthanthrones, azo and monoazo compounds,arylamides, benzimidazolones, BONA lakes, diketopyrrolo-pyrroles,dioxazines, disazo compounds, diarylide compounds, flavanthrones,indanthrones, isoindolinones, isoindolines, metal complexes, monoazosalts, naphthols, b-naphthols, naphthol AS, naphthol lakes, perylenes,perinones, phthalocyanines, pyranthrones, quinacridones, andquinophthalones, and combinations thereof. Where used, the amount of thecolorant or pigment in the polymer blend can be from about greater than0 to about 10 wt %, from about 0.1 to about 5 wt %, or from about 0.25to about 2 wt % of the total weight of the polymer blend. Some colorantshave been described in Zweifel Hans et al., “Plastics AdditivesHandbook,” Hanser Gardner Publications, Cincinnati, Ohio, 5th edition,Chapter 15, pages 813-882 (2001), which is incorporated herein byreference.

Fillers

Optionally, the polymer blends disclosed herein can comprise a fillerwhich can be used to adjust, inter alia, volume, weight, costs, and/ortechnical performance. Any filler known to a person of ordinary skill inthe art may be added to the polymer blends disclosed herein.Non-limiting examples of suitable fillers include talc, calciumcarbonate, chalk, calcium sulfate, clay, kaolin, silica, glass, fumedsilica, mica, wollastonite, feldspar, aluminum silicate, calciumsilicate, alumina, hydrated alumina such as alumina trihydrate, glassmicrosphere, ceramic microsphere, thermoplastic microsphere, barite,wood flour, glass fibers, carbon fibers, marble dust, cement dust,magnesium oxide, magnesium hydroxide, antimony oxide, zinc oxide, bariumsulfate, titanium dioxide, titanates and combinations thereof. In someembodiments, the filler is barium sulfate, talc, calcium carbonate,silica, glass, glass fiber, alumina, titanium dioxide, or a mixturethereof. In other embodiments, the filler is talc, calcium carbonate,barium sulfate, glass fiber or a mixture thereof.

In some embodiments, the inclusion of an adsorptive inorganic additivehas been found to improve the odor properties of the foamed productsprovided herein. The addition of an odor absorber additive such ascharcoal, calcium carbonate or magnesium oxide in the range from about0.1 to about 3 weight percent, or about 0.5 to about 2 weight percent,based on the total composition, is effective in eliminating odors.

Where used, the amount of the filler in the polymer blend can be fromabout greater than 0 to about 80 wt %, from about 0.1 to about 60 wt %,from about 0.5 to about 40 wt %, from about 1 to about 30 wt %, or fromabout 10 to about 40 wt % of the total weight of the polymer blend. Somefillers have been disclosed in U.S. Pat. No. 6,103,803 and Zweifel Hanset al., “Plastics Additives Handbook,” Hanser Gardner Publications,Cincinnati, Ohio, 5th edition, Chapter 17, pages 901-948 (2001), both ofwhich are incorporated herein by reference.

Lubricants

Optionally, the polymer blends disclosed herein can comprise alubricant. In general, the lubricant can be used, inter alia, to modifythe rheology of the molten polymer blends, to improve the surface finishof molded articles, and/or to facilitate the dispersion of fillers orpigments. Any lubricant known to a person of ordinary skill in the artmay be added to the polymer blends disclosed herein. Non-limitingexamples of suitable lubricants include fatty alcohols and theirdicarboxylic acid esters, fatty acid esters of short-chain alcohols,fatty acids, fatty acid amides, metal soaps, oligomeric fatty acidesters, fatty acid esters of long-chain alcohols, montan waxes,polyethylene waxes, polypropylene waxes, natural and synthetic paraffinwaxes, fluoropolymers and combinations thereof. In some embodiments,lubricants comprise an organopolysiloxane. In some embodiments, theorganopolysiloxane can have an average molecular weight not less than40,000 and a viscosity of at least 50.000 cst.

Where used, the amount of the lubricant in the polymer blend can be fromabout greater than 0 to about 5 wt %, from about 0.1 to about 4 wt %, orfrom about 0.1 to about 3 wt % of the total weight of the polymer blend.Some suitable lubricants have been disclosed in Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 5, pages 511-552 (2001), both of which areincorporated herein by reference.

Antistatic Agents

Optionally, the polymer blends disclosed herein can comprise anantistatic agent. Generally, the antistatic agent can increase theconductivity of the polymer blends and to prevent static chargeaccumulation. Any antistatic agent known to a person of ordinary skillin the art may be added to the polymer blends disclosed herein.Non-limiting examples of suitable antistatic agents include conductivefillers (e.g., carbon black, metal particles and other conductiveparticles), fatty acid esters (e.g., glycerol monostearate), ethoxylatedalkylamines, diethanolamides, ethoxylated alcohols, alkylsulfonates,alkylphosphates, quaternary ammonium salts, alkylbetaines andcombinations thereof. Where used, the amount of the antistatic agent inthe polymer blend can be from about greater than 0 to about 5 wt %, fromabout 0.01 to about 3 wt %, or from about 0.1 to about 2 wt % of thetotal weight of the polymer blend. Some suitable antistatic agents havebeen disclosed in Zweifel Hans et al., “Plastics Additives Handbook,”Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 10,pages 627-646 (2001), both of which are incorporated herein byreference.

Cross-Linking Agents

In further embodiments, the polymer blends disclosed herein optionallycomprise a cross-linking agent that can be used to increase thecross-linking density of the polymer blends. Any cross-linking agentknown to a person of ordinary skill in the art may be added to thepolymer blends disclosed herein. Non-limiting examples of suitablecross-linking agents include organic peroxides (e.g., alkyl peroxides,aryl peroxides, peroxyesters, peroxycarbonates, diacylperoxides,peroxyketals, and cyclic peroxides) and silanes (e.g.,vinyltrimethoxysilane, vinyltriethoxysilane,vinyltris(2-methoxyethoxy)silane, vinyltriacetoxysilane,vinylmethyldimethoxysilane, and3-methacryloyloxypropyltrimethoxysilane). Where used, the amount of thecross-linking agent in the polymer blend can be from about greater than0 to about 20 wt %, from about 0.1 to about 15 wt %, or from about 1 toabout 10 wt % of the total weight of the polymer blend. Some suitablecross-linking agents have been disclosed in Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 14, pages 725-812 (2001), both of which areincorporated herein by reference.

The cross-linking of the polymer blends can also be initiated by anyradiation means known in the art, including, but not limited to,electron-beam irradiation, beta irradiation, gamma irradiation, coronairradiation, and UV radiation with or without cross-linking catalyst.U.S. patent application Ser. No. 10/086,057 (published as US2002/0132923A1) and U.S. Pat. No. 6,803,014 disclose electron-beam irradiationmethods that can be used in embodiments of the invention.

Irradiation may be accomplished by the use of high energy, ionizingelectrons, ultra violet rays, X-rays, gamma rays, beta particles and thelike and combination thereof. Preferably, electrons are employed up to70 megarads dosages. The irradiation source can be any electron beamgenerator operating in a range from about 150 kilovolts to about 6megavolts with a power output capable of supplying the desired dosage.The voltage can be adjusted to appropriate levels which may be, forexample, 100,000, 300,000, 1,000,000 or 2,000,000 or 3,000,000 or6,000,000 or higher or lower. Many other apparati for irradiatingpolymeric materials are known in the art. The irradiation is usuallycarried out at a dosage between about 3 megarads to about 35 megarads,preferably between about 8 to about 20 megarads. Further, theirradiation can be carried out conveniently at room temperature,although higher and lower temperatures, for example 0° C. to about 60°C., may also be employed. Preferably, the irradiation is carried outafter shaping or fabrication of the article. Also, in a preferredembodiment, the ethylene interpolymer which has been incorporated with apro-rad additive is irradiated with electron beam radiation at about 8to about 20 megarads.

Crosslinking can be promoted with a crosslinking catalyst, and anycatalyst that will provide this function can be used. Suitable catalystsgenerally include organic bases, carboxylic acids, and organometalliccompounds including organic titanates and complexes or carboxylates oflead, cobalt, iron, nickel, zinc and tin. Dibutyltindilaurate,dioctyltinmaleate, dibutyltindiacetate, dibutyltindioctoate, stannousacetate, stannous octoate, lead naphthenate, zinc caprylate, cobaltnaphthenate; and the like. Tin carboxylate, especiallydibutyltindilaurate and dioctyltinmaleate, are particularly effectivefor this invention. The catalyst (or mixture of catalysts) is present ina catalytic amount, typically between about 0.015 and about 0.035 phr.

Representative pro-rad additives include, but are not limited to, azocompounds, organic peroxides and polyfunctional vinyl or allyl compoundssuch as, for example,. triallyl cyanurate, triallyl isocyanurate,pentaerthritol tetramethacrylate, glutaraldehyde, ethylene glycoldimethacrylate, diallyl maleate, dipropargyl maleate, dipropargylmonoallyl cyanurate, dicumyl peroxide, di-tert-butyl peroxide, t-butylperbenzoate, benzoyl peroxide, cumene hydroperoxide, t-butyl peroctoate,methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexane,lauryl peroxide, tert-butyl peracetate, azobisisobutyl nitrite and thelike and combination thereof. Preferred pro-rad additives for use in thepresent invention are compounds which have polyfunctional (i.e. at leasttwo) moieties such as C═C, C═N or C═O.

At least one pro-rad additive can be introduced to the ethyleneinterpolymer by any method known in the art. However, preferably thepro-rad additive(s) is introduced via a masterbatch concentratecomprising the same or different base resin as the ethyleneinterpolymer. Preferably, the pro-rad additive concentration for themasterbatch is relatively high e.g., about 25 weight percent (based onthe total weight of the concentrate).

The at least one pro-rad additive is introduced to the ethylene polymerin any effective amount. Preferably, the at least one pro-rad additiveintroduction amount is from about 0.001 to about 5 weight percent, morepreferably from about 0.005 to about 2.5 weight percent and mostpreferably from about 0.015 to about 1 weight percent (based on thetotal weight of the ethylene interpolymer.

In addition to electron-beam irradiation, crosslinking can also beeffected by UV irradiation. U.S. Pat. No. 6,709,742 discloses across-linking method by UV irradiation which can be used in embodimentsof the invention. The method comprises mixing a photoinitiator, with orwithout a photocrosslinker, with a polymer before, during, or after afiber is formed and then exposing the fiber with the photoinitiator tosufficient UV radiation to crosslink the polymer to the desired level.The photoinitiators used in the practice of the invention are aromaticketones, e.g., benzophenones or monoacetals of 1,2-diketones. Theprimary photoreaction of the monacetals is the homolytic cleavage of theα-bond to give acyl and dialkoxyalkyl radicals. This type of α-cleavageis known as a Norrish Type I reaction which is more fully described inW. Horspool and D. Armesto, Organic Photochemistry: A ComprehensiveTreatment, Ellis Horwood Limited, Chichester, England, 1992; J. Kopecky,Organic Photochemistry: A Visual Approach, VCH Publishers, Inc., NewYork, N.Y. 1992; N. J. Turro, et al., Acc. Chem. Res., 1972, 5, 92; andJ. T. Banks, et al., J. Am. Chem. Soc., 1993, 115, 2473. The synthesisof monoacetals of aromatic 1,2 diketones, Ar—CO—C(OR)₂—Ar′ is describedin U.S. Pat. No. 4,190,602 and Ger. Offen. 2,337,813. The preferredcompound from this class is 2,2-dimethoxy-2-phenylacetophenone,C₆H₅—CO—C(OCH₃)₂—C₆H₅, which is commercially available from Ciba-Geigyas Irgacure 651. Examples of other aromatic ketones useful in thepractice of this invention as photoinitiators are Irgacure 184, 369,819, 907 and 2959, all available from Ciba-Geigy.

In some embodiments of the invention, the photoinitiator is used incombination with a photocrosslinker. Any photocrosslinker that will uponthe generation of free radicals, link two or more polyolefin backbonestogether through the formation of covalent bonds with the backbones canbe used in this invention. Preferably these photocrosslinkers arepolyfunctional, i.e., they comprise two or more sites that uponactivation will form a covalent bond with a site on the backbone of thecopolymer. Representative photocrosslinkers include, but are not limitedto polyfunctional vinyl or allyl compounds such as, for example,triallyl cyanurate, triallyl isocyanurate, pentaerthritoltetramethacrylate, ethylene glycol dimethacrylate, diallyl maleate,dipropargyl maleate, dipropargyl monoallyl cyanurate and the like.Preferred photocrosslinkers for use in the present invention arecompounds which have polyfunctional (i.e. at least two) moieties.Particularly preferred photocrosslinkers are triallycyanurate (TAC) andtriallylisocyanurate (TAIC).

Certain compounds act as both a photoinitiator and a photocrosslinker inthe practice of this invention. These compounds are characterized by theability to generate two or more reactive species (e.g., free radicals,carbenes, nitrenes, etc.) upon exposure to UV-light and to subsequentlycovalently bond with two polymer chains. Any compound that can preformthese two functions can be used in the practice of this invention, andrepresentative compounds include the sulfonyl azides described in U.S.Pat. Nos. 6,211,302 and 6,284,842.

In another embodiment of this invention, the copolymer is subjected tosecondary crosslinking, i.e., crosslinking other than and in addition tophotocrosslinking. In this embodiment, the photoinitiator is used eitherin combination with a nonphotocrosslinker, e.g., a silane, or thecopolymer is subjected to a secondary crosslinking procedure, e.g,exposure to E-beam radiation. Representative examples of silanecrosslinkers are described in U.S. Pat. No. 5,824,718, and crosslinkingthrough exposure to E-beam radiation is described in U.S. Pat. Nos.5,525,257 and 5,324,576. The use of a photocrosslinker in thisembodiment is optional

At least one photoadditive, i.e., photoinitiator and optionalphotocrosslinker, can be introduced to the copolymer by any method knownin the art. However, preferably the photoadditive(s) is (are) introducedvia a masterbatch concentrate comprising the same or different baseresin as the copolymer. Preferably ,the photoadditive concentration forthe masterbatch is relatively high e.g., about 25 weight percent (basedon the total weight of the concentrate).

The at least one photoadditive is introduced to the copolymer in anyeffective amount. Preferably, the at least one photoadditiveintroduction amount is from about 0.001 to about 5, more preferably fromabout 0.005 to about 2.5 and most preferably from about 0.015 to about1, wt % (based on the total weight of the copolymer).

The photoinitiator(s) and optional photocrosslinker(s) can be addedduring different stages of the fiber or film manufacturing process. Ifphotoadditives can withstand the extrusion temperature, a polyolefinresin can be mixed with additives before being fed into the extruder,e.g., via a masterbatch addition. Alternatively, additives can beintroduced into the extruder just prior the slot die, but in this casethe efficient mixing of components before extrusion is important. Inanother approach, polyolefin fibers can be drawn without photoadditives,and a photoinitiator and/or photocrosslinker can be applied to theextruded fiber via a kiss-roll, spray, dipping into a solution withadditives, or by using other industrial methods for post-treatment. Theresulting fiber with photoadditive(s) is then cured via electromagneticradiation in a continuous or batch process. The photo additives can beblended with the polyolefin using conventional compounding equipment,including single and twin-screw extruders.

The power of the electromagnetic radiation and the irradiation time arechosen so as to allow efficient crosslinking without polymer degradationand/or dimensional defects. The preferred process is described in EP 0490 854 B1. Photoadditive(s) with sufficient thermal stability is (are)premixed with a polyolefin resin, extruded into a fiber, and irradiatedin a continuous process using one energy source or several units linkedin a series. There are several advantages to using a continuous processcompared with a batch process to cure a fiber or sheet of a knittedfabric which are collected onto a spool.

Irradiation may be accomplished by the use of UV-radiation. Preferably,UV-radiation is employed up to the intensity of 100 J/cm². Theirradiation source can be any UV-light generator operating in a rangefrom about 50 watts to about 25000 watts with a power output capable ofsupplying the desired dosage. The wattage can be adjusted to appropriatelevels which may be, for example, 1000 watts or 4800 watts or 6000 wattsor higher or lower. Many other apparati for UV-irradiating polymericmaterials are known in the art. The irradiation is usually carried outat a dosage between about 3 J/cm² to about 500 J/scm^(2,), preferablybetween about 5 J/cm² to about 100 J/cm². Further, the irradiation canbe carried out conveniently at room temperature, although higher andlower temperatures, for example 0° C. to about 60° C., may also beemployed. The photocrosslinking process is faster at highertemperatures. Preferably, the irradiation is carried out after shapingor fabrication of the article. In a preferred embodiment, the copolymerwhich has been incorporated with a photoadditive is irradiated withUV-radiation at about 10 J/cm² to about 50 J/cm².

Blowing Agents

Foaming agents suitable for use in the gaskets disclosed herein includephysical blowing agents which function as gas sources by going through achange of physical state. Volatile liquids produce gas by passing fromthe liquid to gaseous state, whereas compressed gases are dissolvedunder pressure in the melted polymer. Chemical blowing agents producegas by a chemical reaction, either by a thermal decomposition or by areaction between two components.

Suitable physical blowing agents include pentanes (e.g., n-pentane,2-methylbutane, 2,2-dimethylpropane, 1-pentane and cyclopentane),hexanes (e.g., n-hexane, 2-methylpentane, 3-methylpentane,2,3-dimethylbutane, 2,2-dimethylbutane, 1-hexene, cyclohexane), heptanes(e.g., n-heptane, 2-methylhexane, 2,2-dimethylpentane,2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane,3-ethylpentane, 2,2,3-trimethylbutane, 1-heptene), benzene, toluene,dichloromethane, trichloromethane, trichloroethylene,tetrachloromethane, 1,2-dichloroethane, trichlorofluoromethane,1,1,2-trichlorotrifluoroethane, methanol, ethanol, 2-propanol, ethylether, isopropyl ether, acetone, methyl ethyl ketone, and methylenechloride. Suitable gaseous blowing agents include carbon dioxide andnitrogen.

Suitable chemical blowing agents include sodium bicarbonate,dinitrosopentamethylenetetramine, sulfonyl hydrazides, azodicarbonamide(e.g., Celogen™ AZNP 130 made by Uniroyal Chemical), p-toluenesulfonylsemicarbazide, 5-phenyltetrazole, diisopropylhydrazodicarboxylate,5-phenyl-3,6-dihydro-1,3,4-oxadiazin-2-one, and sodium borohydride.

The amount of blowing agent is dependent on the desired densityreduction. One can calculate the amount of blowing agent required byknowing the volume of gas produced per gram of blowing agent at a giventemperature and the desired density reduction (or target density) for adesired application. For chemical blowing agents the range is 0.1 to 4%by weight and more preferably 0.25 to 2% by weight. This range can alsobe adjusted by the addition of activation agents (sometimes referred toas coagents) such as (zinc oxide, zinc stearate).

Foams useful for making the gaskets claimed herein can be made asdescribed in U.S. Pat. No. 5,288,762, U.S. Pat. No. 5,340,840, U.S. Pat.No. 5,369,136, U.S. Pat. No. 5,387,620 and U.S. Pat. No. 5,407,965, thedisclosures of each of which are incorporated herein by reference intheir entirety.

Preparation of the Polymer Blends

The ingredients of the polymer blends, i.e., the ethylene/α-olefininterpolymer, the at least one other polymer component, such as theelastomer, the polyolefin or the polar polymer and the optionaladditives, can be mixed or blended using methods known to a person ofordinary skill in the art, preferably methods that can provide asubstantially homogeneous distribution of the polyolefin and/or theadditives in the ethylene/α-olefin interpolymer. Non-limiting examplesof suitable blending methods include melt blending, solvent blending,extruding, and the like.

In some embodiments, the ingredients of the polymer blends are meltblended by a method as described by Guerin et al. in U.S. Pat. No.4,152,189. First, all solvents, if there are any, are removed from theingredients by heating to an appropriate elevated temperature of about100° C. to about 200° C. or about 150° C. to about 175° C. at a pressureof about 5 torr (667 Pa) to about 10 torr (1333 Pa). Next, theingredients are weighed into a vessel in the desired proportions and thepolymer blend is formed by heating the contents of the vessel to amolten state while stirring.

In other embodiments, the ingredients of the polymer blends areprocessed using solvent blending. First, the ingredients of the desiredpolymer blend are dissolved in a suitable solvent and the mixture isthen mixed or blended. Next, the solvent is removed to provide thepolymer blend.

In further embodiments, physical blending devices that providedispersive mixing, distributive mixing, or a combination of dispersiveand distributive mixing can be useful in preparing homogenous blends.Both batch and continuous methods of physical blending can be used.Non-limiting examples of batch methods include those methods usingBRABENDER® mixing equipments (e.g., BRABENDER PREP CENTER®, availablefrom C.W. Brabender Instruments, Inc., South Hackensack, N.J.) orBANBURY® internal mixing and roll milling (available from FarrelCompany, Ansonia, Conn.) equipment. Non-limiting examples of continuousmethods include single screw extruding, twin screw extruding, diskextruding, reciprocating single screw extruding, and pin barrel singlescrew extruding. In some embodiments, the additives can be added into anextruder through a feed hopper or feed throat during the extrusion ofthe ethylene/α-olefin interpolymer, the polyolefin or the polymer blend.The mixing or blending of polymers by extrusion has been described in C.Rauwendaal, “Polymer Extrusion”, Hanser Publishers, New York, N.Y.,pages 322-334 (1986), which is incorporated herein by reference.

When one or more additives are required in the polymer blends, thedesired amounts of the additives can be added in one charge or multiplecharges to the ethylene/α-olefin interpolymer, the polyolefin or thepolymer blend. Furthermore, the addition can take place in any order. Insome embodiments, the additives are first added and mixed or blendedwith the ethylene/α-olefin interpolymer and then the additive-containinginterpolymer is blended with the polyolefin. In other embodiments, theadditives are first added and mixed or blended with the polyolefin andthen the additive-containing polyolefin is blended with theethylene/α-olefin interpolymer. In further embodiments, theethylene/α-olefin interpolymer is blended with the polyolefin first andthen the additives are blended with the polymer blend.

Alternatively, master batches containing high concentrations of theadditives can be used. In general, master batches can be prepared byblending either the ethylene/α-olefin interpolymer, the polyolefin orthe polymer blend with high concentrations of additives. The masterbatches can have additive concentrations from about 1 to about 50 wt %,from about 1 to about 40 wt %, from about 1 to about 30 wt %, or fromabout 1 to about 20 wt % of the total weight of the polymer blend. Themaster batches can then be added to the polymer blends in an amountdetermined to provide the desired additive concentrations in the endproducts. In some embodiments, the master batch contains a slip agent,an anti-blocking agent, a plasticizer, an antioxidant, a UV stabilizer,a colorant or pigment, a filler, a lubricant, an antifogging agent, aflow aid, a coupling agent, a cross-linking agent, a nucleating agent, asurfactant, a solvent, a flame retardant, an antistatic agent, or acombination thereof. In other embodiment, the master batch contains aslip agent, an anti-blocking agent or a combination thereof. In otherembodiment, the master batch contains a slip agent.

Applications of Polymer Blends

The polymer blends disclosed herein can be used to manufacture durablearticles for the automotive, construction, medical, food and beverage,electrical, appliance, business machine, and consumer markets. In someembodiments, the polymer blends are used to manufacture flexible durableparts or articles selected from toys, grips, soft touch handles, bumperrub strips, floorings, auto floor mats, wheels, casters, furniture andappliance feet, tags, seals, gaskets such as static and dynamic gaskets,automotive doors, bumper fascia, grill components, rocker panels, hoses,linings, office supplies, seals, liners, diaphragms, tubes, lids,stoppers, plunger tips, delivery systems, kitchen wares, shoes, shoebladders and shoe soles. In other embodiments, the polymer blends can beused to manufacture durable parts or articles that require a hightensile strength and low compression set. In further embodiments, thepolymer blends can be used to manufacture durable parts or articles thatrequire a high upper service temperature and low modulus.

Gasket Configurations

Gaskets can have many different forms, including “o-rings” and flatseals (e.g., “film-like” gaskets having a thickness commensurate withthe intended use).

Suitable end uses include gaskets for metal and plastic closures, aswell as other gasket applications. These applications include beveragecap liners, hot fill juice cap liners, polypropylene cap liners, steelor aluminum cap liners, high density polyethylene cap liners, windowglass gaskets, sealed containers, closure caps, gaskets for medicaldevices, filter elements, pressure venting gaskets, hot melt gaskets,easy twist off caps, electrochemical cell gaskets, refrigerator gaskets,galvanic cell gaskets, leak proof cell gaskets, waterproofing sheet,reusable gaskets, synthetic cork like materials, thin cellelectromembrane separator, magnetic rubber materials, disc gaskets foralcoholic beverage bottle caps, freeze resistant seal rings, gaskets forplastic castings, expansion joints and waterstops, corrosion-resistantconduit connectors, flexible magnetic plastics, pipe joint seals,integral weatherproof plastic lid and hinge for electrical outlets,magnetic faced foamed articles, jar rings, flexible gaskets, glassseals, tamper evident sealing liners, pressure applicators, combinedbottle cap and straw structures, large condiment bottle liners, metalcaps for applesauce or salsa jars, home canning jars, “crowns,” and thelike.

Gaskets made from the substantially linear or homogeneous linearethylene polymers have numerous advantages, especially when used infood-stuff applications. These include: improved taste and odor overincumbent polymer gaskets such as ethylene/vinyl acetate; low adhesionto polar substrates (e.g., polyethylene terephthalate, glass) which isuseful for low torque removal of the closure/cap; low extractables(e.g., less than about 5.5% by weight) (also useful for food-stuffs,especially regarding regulatory compliance); good adhesion to non-polarsubstrates (e.g., polypropylene and high density polyethylene (eitherlinear homopolymer polyethylene or linear heterogeneous high densitypolyethylene)); Good adhesion in a cap or crown can be described assufficiently adhering to the substrate. A gasket exhibits this typeadhesion when it can only be removed under a cohesive failure mode.Adhesion to metal (such as beer crowns) requires a lacquer that is bothcompatible with the polymer system and bonds to the metal. One suchexample that provides good adhesion is a modified polyester provided byWatson Standard (#40-207). Modified epoxy lacquers have alsodemonstrated good adhesion. Additional benefits include adequate gas andwater barrier properties; high melting point relative to incumbentpolymers (e.g., ethylene/vinyl acetate); good stress crack resistance;good chemical resistance; variable hardness (useful for specificpackaging which may require more or less gasket stiffness, depending onthe degree of torque required to seal the container and the internalpressure of the container).

In certain embodiments, the ethylene/alpha-olefin polymers used in thepresent invention are present in the three component composition used inthe gasket in an amount in the range from about 80% to about 97.5% bytotal weight of the three component composition. Preferably, theethylene/alpha-olefin polymers used in the present invention can befound in the three component gasket compositions in the range from about85% to about 97.5%. More preferably, the ethylene/alpha-olefin polymersused in the present invention can be found in the gasket composition inthe range of about 90% to about 97.5%. The three component compositioncan be admixed with other materials, such as styrene/butadiene/styreneblock polymers (“SBS”). Preferably, the three component compositioncomprises from about 50 percent, especially from about 80 percent, to100 percent of the gasket, by weight of the gasket.

The gaskets comprising the ethylene/alpha-olefin polymers used in thepresent invention should be hard enough to withstand compression, butstill soft enough such that an adequate seal is formed. Thus, thehardness of the polymer enables varying gaskets to be made, depending onthe use. Hardness is measured herein as “Shore A” hardness (asdetermined using ASTM D-2240). For the ethylene/alpha-olefin polymersused in the present invention which comprise the gaskets, the Shore Ahardness ranges from about 50 to about 100, even without the use ofpetroleum oils commonly included to reduce the hardness of the polymerand resulting gasket.

In some embodiments, the gaskets provided herein comprise additives suchas antioxidants (e.g., hindered phenolics (e.g., Irganox.RTM. 1010 madeby Ciba Geigy Corp.), phosphites (e.g., Irgafos.RTM. 168 made by CibaGeigy Corp.)), cling additives (e.g., polyisobutylene (PIB)), slipadditives (e.g., erucamide), antiblock additives, pigments, and the likecan also be included in the gasket compositions, to the extent that theydo not interfere with the improved properties described herein.

Various gasket manufacturing techniques include those disclosed in U.S.Pat. No. 5,215,587 (McConnellogue et al.); U.S. Pat. No. 4,085,186(Rainer); U.S. Pat. No. 4,619,848 (Knight et al.); U.S. Pat. No.5,104,710 (Knight); U.S. Pat. No. 4,981,231 (Knight); U.S. Pat. No.4,717,034 (Mumford); U.S. Pat. No. 3,786,954 (Shull); U.S. Pat. No.3,779,965 (Lefforge et al.); U.S. Pat. No. 3,493,453 (Ceresa et al.);U.S. Pat. No. 3,183,144 (Caviglia); U.S. Pat. No. 3,300,072 (Caviglia);U.S. Pat. No. 4,984,703 (Burzynski); U.S. Pat. No. 3,414,938 (Caviglia);U.S. Pat. No. 4,939,859 (Bayer); U.S. Pat. No. 5,137,164 (Bayer); andU.S. Pat. No. 5,000,992 (Kelch). The disclosure of each of the precedingUnited States patents is incorporated herein in its entirety byreference. Preferably, the gasket is made in a single step process byextruding a portion of the foaming ethylene/alpha-olefin polymers usedin the present invention and then immediately compression molding thatportion into a gasket, especially where the gasket adheres to asubstrate such as phenolic, epoxy or polyester lacqueres.

The gaskets claimed herein are different from those gaskets made byextruded sheets or films by conventional techniques as blown, cast orextrusion coated films, followed by stamping or cutting the gasket fromthe sheet or film since substantial waste is avoided and more controlover gasket dimensions in 1-step process; another advantage of the1-step process is achieving lower gasket thickness (e.g., from about 5mils to about 50 mils).

Preferably, the 1-step process for forming a gasket having a Shore Ahardness from about 40 to about 95, comprising the steps of:

-   -   (a) combining at least one ethylene/alpha-olefin interpolymer        having the properties specified herein, at least one        ethylene/carboxylic acid interpolymer or ionomer thereof, at        least one slip agent, with at least one blowing agent to from a        mixture,    -   (b) extruding the mixture into a pellet,    -   (c) cutting the extruded mixture into a pellet,    -   (d) positioning the cut extruded mixture into a closure, and    -   (e) compression shaping the positioned mixture in the closure.        More preferably, for closures having a 28 mm diameter, the cut        pellet weighs from about 120 mg to about 300 mg.

Multilayer film structures are also suitable for making the gasketsdisclosed herein, with the proviso that at least one layer (preferablythe inner layer which is located adjacent to the product) comprises thehomogeneously branched linear or homogeneously branched substantiallylinear ethylene interpolymer. Foam multilayer gaskets comprising thehomogeneously branched linear or homogenously branched substantiallylinear ethylene interpolymers are also useful in the present invention.

In some embodiments, the polymer blends disclosed herein can be used tomanufacture gaskets with improved taste and odor properties. The use ofethylene/α-olefin interpolymers offer less sensitivity to temperature,for example in the range from below 40° F. to 158° F., for key closureliner or gasket physical properties. The ethylene/α-olefin interpolymersshow reduced change in properties versus other polymer systems, over thetemperature range from below 40° F. to 158° F. The key polymerproperties are relatively insensitive to temperature in the keyoperational temperature range.

The sealing gasket compositions of the present invention may alsoinclude various other components that are known to those skilled in theart. Examples of other materials which may be included in the gasketcomposition are a lubricants and colorants. Examples of suitablelubricants include, but are not limited to, stearates and fatty amides,such as Kemmamide-E™ (also called erucamide), which can be obtained fromthe Witco Corporation. Examples of suitable, colorants include, but arenot limited to, thaloblue, which may be obtained from Quantum ChemicalCorporation.

For closure liner application used in more extreme conditions, theaddition of 30% or less of a very high molecular weight elastomer suchas an SEBS polymer of melt index less than 0.1 to ethylene/α-olefininterpolymers can result in a composition with physical propertiessimilar to a the very high molecular weight elastomer. This blendcomposition offers advantages over the very high molecular weightelastomer including: improved processability and reduced cost. The veryhigh molecular weight elastomers by themselves have such high viscositythat they can not be processed in production equipment used to produceclosure liners.

The ethylene/α-olefin interpolymers offer unique, advantagedcombinations of properties of processability and physical propertiesthat unmodified elastomers do not possess. In particular, elastomerssuch as SEBS should be of very high molecular weight to exhibit thephysical properties required for closure liner application but at thesemolecular weight the elastomers are totally unprocessable in standardclosure liner equipment. Typically these polymers must be modified withextenders and other polymers to obtain sufficient processability.

The ethylene/α-olefin interpolymers blends with polyolefin polymers,such as LLDPE, SEBS, and others show synergistic effect in compressionset.

Manufacture of Articles

The polymer blends can be used to prepare these durable parts orarticles with known polymer processes such as extrusion (e.g., sheetextrusion and profile extrusion), injection molding, molding, rotationalmolding, and blow molding. In general, extrusion is a process by which apolymer is propelled continuously along a screw through regions of hightemperature and pressure where it is melted and compacted, and finallyforced through a die. The extruder can be a single screw extruder, amultiple screw extruder, a disk extruder or a ram extruder. The die canbe a film die, blown film die, sheet die, pipe die, tubing die orprofile extrusion die. The extrusion of polymers has been described inC. Rauwendaal, “Polymer Extrusion”, Hanser Publishers, New York, N.Y.(1986); and M. J. Stevens, “Extruder Principals and Operation,”Ellsevier Applied Science Publishers, New York, N.Y. (1985), both ofwhich are incorporated herein by reference in their entirety.

Injection molding is also widely used for manufacturing a variety ofplastic parts for various applications. In general, injection molding isa process by which a polymer is melted and injected at high pressureinto a mold, which is the inverse of the desired shape, to form parts ofthe desired shape and size. The mold can be made from metal, such assteel and aluminum. The injection molding of polymers has been describedin Beaumont et al., “Successful Injection Molding: Process, Design, andSimulation,” Hanser Gardner Publications, Cincinnati, Ohio (2002), whichis incorporated herein by reference in its entirety.

Molding is generally a process by which a polymer is melted and led intoa mold, which is the inverse of the desired shape, to form parts of thedesired shape and size. Molding can be pressureless orpressure-assisted. The molding of polymers is described in Hans-GeorgElias “An Introduction to Plastics,” Wiley-VCH, Weinhei, Germany, pp.161-165 ( 2003), which is incorporated herein by reference.

Rotational molding is a process generally used for producing hollowplastic products. By using additional post-molding operations, complexcomponents can be produced as effectively as other molding and extrusiontechniques. Rotational molding differs from other processing methods inthat the heating, melting, shaping, and cooling stages all occur afterthe polymer is placed in the mold, therefore no external pressure isapplied during forming. The rotational molding of polymers has beendescribed in Glenn Beall, “Rotational Molding: Design, Materials &Processing,” Hanser Gardner Publications, Cincinnati, Ohio (1998), whichis incorporated herein by reference in its entirety.

Blow molding can be used for making hollow plastics containers. Theprocess includes placing a softened polymer in the center of a mold,inflating the polymer against the mold walls with a blow pin, andsolidifying the product by cooling. There are three general types ofblow molding: extrusion blow molding, injection blow molding, andstretch blow molding. Injection blow molding can be used to processpolymers that cannot be extruded. Stretch blow molding can be used fordifficult to blow crystalline and crystallizable polymers such aspolypropylene. The blow molding of polymers has been described in NormanC. Lee, “Understanding Blow Molding,” Hanser Gardner Publications,Cincinnati, Ohio (2000), which is incorporated herein by reference inits entirety.

The following examples are presented to exemplify embodiments of theinvention. All numerical values are approximate. When numerical rangesare given, it should be understood that embodiments outside the statedranges may still fall within the scope of the invention. Specificdetails described in each example should not be construed as necessaryfeatures of the invention.

EXAMPLES Testing Methods

In the examples that follow, the following analytical techniques areemployed:

GPC Method for Samples 1-4 and A-C

An automated liquid-handling robot equipped with a heated needle set to160° C. is used to add enough 1,2,4-trichlorobenzene stabilized with 300ppm Ionol to each dried polymer sample to give a final concentration of30 mg/mL. A small glass stir rod is placed into each tube and thesamples are heated to 160° C. for 2 hours on a heated, orbital-shakerrotating at 250 rpm. The concentrated polymer solution is then dilutedto 1 mg/ml using the automated liquid-handling robot and the heatedneedle set to 160° C.

A Symyx Rapid GPC system is used to determine the molecular weight datafor each sample. A Gilson 350 pump set at 2.0 ml/min flow rate is usedto pump helium-purged 1,2-dichlorobenzene stabilized with 300 ppm Ionolas the mobile phase through three Plgel 10 micrometer (μm) Mixed B 300mm×7.5 mm columns placed in series and heated to 160° C. A Polymer LabsELS 1000 Detector is used with the Evaporator set to 250° C., theNebulizer set to 165° C., and the nitrogen flow rate set to 1.8 SLM at apressure of 60-80 psi (400-600 kPa) N₂. The polymer samples are heatedto 160° C. and each sample injected into a 250 μl loop using theliquid-handling robot and a heated needle. Serial analysis of thepolymer samples using two switched loops and overlapping injections areused. The sample data is collected and analyzed using Symyx Epoch™software. Peaks are manually integrated and the molecular weightinformation reported uncorrected against a polystyrene standardcalibration curve.

Standard CRYSTAF Method

Branching distributions are determined by crystallization analysisfractionation (CRYSTAF) using a CRYSTAF 200 unit commercially availablefrom PolymerChar, Valencia, Spain. The samples are dissolved in 1,2,4trichlorobenzene at 160° C. (0.66 mg/mL) for 1 hr and stabilized at 95°C. for 45 minutes. The sampling temperatures range from 95 to 30° C. ata cooling rate of 0.2° C./min. Ali infrared detector is used to measurethe polymer solution concentrations. The cumulative solubleconcentration is measured as the polymer crystallizes while thetemperature is decreased. The analytical derivative of the cumulativeprofile reflects the short chain branching distribution of the polymer.

The CRYSTAF peak temperature and area are identified by the peakanalysis module included in the CRYSTAF Software (Version 2001.b,PolymerChar, Valencia, Spain). The CRYSTAF peak finding routineidentifies a peak temperature as a maximum in the dW/dT curve and thearea between the largest positive inflections on either side of theidentified peak in the derivative curve. To calculate the CRYSTAF curve,the preferred processing parameters are with a temperature limit of 70°C. and with smoothing parameters above the temperature limit of 0.1, andbelow the temperature limit of 0.3.

DSC Standard Method (Excluding Samples 1-4 and A-C)

Differential Scanning Calorimetry results are determined using a TAImodel Q1000 DSC equipped with an RCS cooling accessory and anautosampler. A nitrogen purge gas flow of 50 ml/min is used. The sampleis pressed into a thin film and melted in the press at about 175° C. andthen air-cooled to room temperature (25° C.). 3-10 mg of material isthen cut into a 6 mm diameter disk, accurately weighed, placed in alight aluminum pan (ca 50 mg), and then crimped shut. The thermalbehavior of the sample is investigated with the following temperatureprofile. The sample is rapidly heated to 180° C. and held isothermal for3 minutes in order to remove any previous thermal history. The sample isthen cooled to −40° C. at 10° C./min cooling rate and held at −40° C.for 3 minutes. The sample is then heated to 150° C. at 10° C./min.heating rate. The cooling and second heating curves are recorded.

The DSC melting peak is measured as the maximum in heat flow rate (W/g)with respect to the linear baseline drawn between −30° C. and end ofmelting. The heat of fusion is measured as the area under the meltingcurve between −30° C. and the end of melting using a linear baseline.

GPC Method (Excluding Samples 1-4 and A-C)

The gel permeation chromatographic system consists of either a PolymerLaboratories Model PL-210 or a Polymer Laboratories Model PL-220instrument. The column and carousel compartments are operated at 140° C.Three Polymer Laboratories 10-micron Mixed-B columns are used. Thesolvent is 1,2,4 trichlorobenzene. The samples are prepared at aconcentration of 0.1 grams of polymer in 50 milliliters of solventcontaining 200 ppm of butylated hydroxytoluene (BHT). Samples areprepared by agitating lightly for 2 hours at 160° C. The injectionvolume used is 100 microliters and the flow rate is 1.0 ml/minute.

Calibration of the GPC column set is performed with 21 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000, arranged in 6 “cocktail” mixtures with at least adecade of separation between individual molecular weights. The standardsare purchased from Polymer Laboratories (Shropshire, UK). Thepolystyrene standards are prepared at 0.025 grams in 50 milliliters ofsolvent for molecular weights equal to or greater than 1,000,000, and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards are dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)): M_(polyethylene)=0.431 (M_(polystyrene)).

Polyethylene equivalent molecular weight calculations are performedusing Viscotek TriSEC software Version 3.0.

Compression Set

Compression set is measured according to ASTM D 395. The sample isprepared by stacking 25.4 mm diameter round discs of 3.2 mm, 2.0 mm, and0.25 mm thickness until a total thickness of 12.7 mm is reached. Thediscs are cut from 12.7 cm×12.7 cm compression molded plaques moldedwith a hot press under the following conditions: zero pressure for 3 minat 190° C., followed by 86 MPa for 2 min at 190° C., followed by coolinginside the press with cold running water at 86 MPa.

Density

Samples for density measurement are prepared according to ASTM D 1928.Measurements are made within one hour of sample pressing using ASTMD792, Method B.

Flexural/Secant Modulus/Storage Modulus

Samples are compression molded using ASTM D 1928. Flexural and 2 percentsecant moduli are measured according to ASTM D-790. Storage modulus ismeasured according to ASTM D 5026-01 or equivalent technique.

Optical Properties

Films of 0.4 mm thickness are compression molded using a hot press(Carver Model #4095-4PR1001R). The pellets are placed betweenpolytetrafluoroethylene sheets, heated at 190° C. at 55 psi (380 kPa)for 3 min, followed by 1.3 MPa for 3 min, and then 2.6 MPa for 3 min.The film is then cooled in the press with running cold water at 1.3 MPafor 1 min. The compression molded films are used for opticalmeasurements, tensile behavior, recovery, and stress relaxation.

Clarity is measured using BYK Gardner Haze-gard as specified in ASTM D1746.

45° gloss is measured using BYK Gardner Glossmeter Microgloss 45° asspecified in ASTM D-2457

Internal haze is measured using BYK Gardner Haze-gard based on ASTM D1003 Procedure A. Mineral oil is applied to the film surface to removesurface scratches.

Mechanical Properties—Tensile, Hysteresis, and Tear

Stress-strain behavior in uniaxial tension is measured using ASTM D 1708microtensile specimens. Samples are stretched with an Instron at 500%min⁻¹ at 21° C. Tensile strength and elongation at break are reportedfrom an average of 5 specimens.

100% and 300% Hysteresis is determined from cyclic loading to 100% and300% strains using ASTM D 1708 microtensile specimens with an Instron™instrument. The sample is loaded and unloaded at 267% min⁻¹ for 3 cyclesat 21° C. Cyclic experiments at 300% and 80° C. are conducted using anenvironmental chamber. In the 80° C. experiment, the sample is allowedto equilibrate for 45 minutes at the test temperature before testing. Inthe 21° C., 300% strain cyclic experiment, the retractive stress at 150%strain from the first unloading cycle is recorded. Percent recovery forall experiments are calculated from the first unloading cycle using thestrain at which the load returned to the base line. The percent recoveryis defined as:

${\% \mspace{14mu} {Recovery}} = {\frac{ɛ_{f} - ɛ_{s}}{ɛ_{f}} \times 100}$

where ε_(f) is the strain taken for cyclic loading and ε_(s) is thestrain where the load returns to the baseline during the 1^(st)unloading cycle.

Stress relaxation is measured at 50 percent strain and 37° C. for 12hours using an Instron™ instrument equipped with an environmentalchamber. The gauge geometry was 76 mm×25 mm×0.4 mm. After equilibratingat 37° C. for 45 min in the environmental chamber, the sample wasstretched to 50% strain at 333% min⁻¹. Stress was recorded as a functionof time for 12 hours. The percent stress relaxation after 12 hours wascalculated using the formula:

${\% \mspace{14mu} {Stress}\mspace{14mu} {Relaxation}} = {\frac{L_{0} - L_{12}}{L_{0}} \times 100}$

where L₀ is the load at 50% strain at 0 time and L₁₂ is the load at 50percent strain after 12 hours.

Tensile notched tear experiments are carried out on samples having adensity of 0.88 g/cc or less using an Instron™ instrument. The geometryconsists of a gauge section of 76 mm×13 mm×0.4 mm with a 2 mm notch cutinto the sample at half the specimen length. The sample is stretched at508 mm min⁻¹ at 21° C. until it breaks. The tear energy is calculated asthe area under the stress-elongation curve up to strain at maximum load.An average of at least 3 specimens are reported.

TMA

Thermal Mechanical Analysis (Penetration Temperature) is conducted on 30mm diameter×3.3 mm thick, compression molded discs, formed at 180° C.and 10 MPa molding pressure for 5 minutes and then air quenched. Theinstrument used is a TMA 7, brand available from Perkin-Elmer. In thetest, a probe with 1.5 mm radius tip (P/N N519-0416) is applied to thesurface of the sample disc with 1N force. The temperature is raised at5° C./min from 25° C. The probe penetration distance is measured as afunction of temperature. The experiment ends when the probe haspenetrated 1 mm into the sample.

DMA

Dynamic Mechanical Analysis (DMA) is measured on compression moldeddisks formed in a hot press at 180° C. at 10 MPa pressure for 5 minutesand then water cooled in the press at 90° C./min. Testing is conductedusing an ARES controlled strain rheometer (TA instruments) equipped withdual cantilever fixtures for torsion testing.

A 1.5 mm plaque is pressed and cut in a bar of dimensions 32×12 mm. Thesample is clamped at both ends between fixtures separated by 10 mm (gripseparation ΔL) and subjected to successive temperature steps from −100°C. to 200° C. (5° C. per step). At each temperature the torsion modulusG′ is measured at an angular frequency of 10 rad/s, the strain amplitudebeing maintained between 0.1 percent and 4 percent to ensure that thetorque is sufficient and that the measurement remains in the linearregime.

An initial static force of 10 g is maintained (auto-tension mode) toprevent slack in the sample when thermal expansion occurs. As aconsequence, the grip separation ΔL increases with the temperature,particularly above the melting or softening point of the polymer sample.The test stops at the maximum temperature or when the gap between thefixtures reaches 65 mm.

Melt Index

Melt index, or I₂, is measured in accordance with ASTM D 1238, Condition190° C./2.16 kg. Melt index, or 110 is also measured in accordance withASTM D 1238, Condition 190° C./10 kg.

ATREF

Analytical temperature rising elution fractionation (ATREF) analysis isconducted according to the method described in U.S. Pat. No. 4,798,081and Wilde, L.; Ryle, T. R.; Knobeloch, D. C.; Peat, I. R.; Determinationof Branching Distributions in Polyethylene and Ethylene Copolymers, J.Polym. Sci., 20, 441-455 (1982), which are incorporated by referenceherein in their entirety. The composition to be analyzed is dissolved intrichlorobenzene and allowed to crystallize in a column containing aninert support (stainless steel shot) by slowly reducing the temperatureto 20° C. at a cooling rate of 0.1° C./min. The column is equipped withan infrared detector. An ATREF chromatogram curve is then generated byeluting the crystallized polymer sample from the column by slowlyincreasing the temperature of the eluting solvent (trichlorobenzene)from 20 to 120° C. at a rate of 1.5° C./min.

¹³C NMR Analysis

The samples are prepared by adding approximately 3 g of a 50/50 mixtureof tetrachloroethane-d²/orthodichlorobenzene to 0.4 g sample in a 10 mmNMR tube. The samples are dissolved and homogenized by heating the tubeand its contents to 150° C. The data are collected using a JEOL Eclipse™400 MHz spectrometer or a Varian Unity Plus™ 400 MHz spectrometer,corresponding to a ¹³C resonance frequency of 100.5 MHz. The data areacquired using 4000 transients per data file with a 6 second pulserepetition delay. To achieve minimum signal-to-noise for quantitativeanalysis, multiple data files are added together. The spectral width is25,000 Hz with a minimum file size of 32K data points. The samples areanalyzed at 130° C. in a 10 mm broad band probe. The comonomerincorporation is determined using Randall's triad method (Randall, J.C.; JMS-Rev. Macromol. Chem. Phys., C29, 201-317 (1989), which isincorporated by reference herein in its entirety.

Polymer Fractionation by TREF

Large-scale TREF fractionation is carried by dissolving 15-20 g ofpolymer in 2 liters of 1,2,4-trichlorobenzene (TCB)by stirring for 4hours at 160° C. The polymer solution is forced by 15 psig (100 kPa)nitrogen onto a 3 inch by 4 foot (7.6 cm×12 cm) steel column packed witha 60:40 (v:v) mix of 30-40 mesh (600-425 μm) spherical, technicalquality glass beads (available from Potters Industries, HC 30 Box 20,Brownwood, Tex., 76801) and stainless steel, 0.028″ (0.7 mm) diametercut wire shot (available from Pellets, Inc. 63 Industrial Drive, NorthTonawanda, N.Y., 14120). The column is immersed in a thermallycontrolled oil jacket, set initially to 160° C. The column is firstcooled ballistically to 125° C., then slow cooled to 20° C. at 0.04° C.per minute and held for one hour. Fresh TCB is introduced at about 65ml/min while the temperature is increased at 0.167° C. per minute.

Approximately 2000 ml portions of eluant from the preparative TREFcolumn are collected in a 16 station, heated fraction collector. Thepolymer is concentrated in each fraction using a rotary evaporator untilabout 50 to 100 ml of the polymer solution remains. The concentratedsolutions are allowed to stand overnight before adding excess methanol,filtering, and rinsing (approx. 300-500 ml of methanol including thefinal rinse). The filtration step is performed on a 3 position vacuumassisted filtering station using 5.0 μm polytetrafluoroethylene coatedfilter paper (available from Osmonics Inc., Cat# Z50WP04750). Thefiltrated fractions are dried overnight in a vacuum oven at 60° C. andweighed on an analytical balance before further testing.

Melt Strength

Melt Strength (MS) is measured by using a capillary rheometer fittedwith a 2.1 mm diameter, 20:1 die with an entrance angle of approximately45 degrees. After equilibrating the samples at 190° C. for 10 minutes,the piston is run at a speed of 1 inch/minute (2.54 cm/minute). Thestandard test temperature is 190° C. The sample is drawn uniaxially to aset of accelerating nips located 100 mm below the die with anacceleration of 2.4 mm/sec². The required tensile force is recorded as afunction of the take-up speed of the nip rolls. The maximum tensileforce attained during the test is defined as the melt strength. In thecase of polymer melt exhibiting draw resonance, the tensile force beforethe onset of draw resonance was taken as melt strength. The meltstrength is recorded in centiNewtons (“cN”).

Catalysts

The term “overnight”, if used, refers to a time of approximately 16-18hours, the term “room temperature”, refers to a temperature of 20-25°C., and the term “mixed alkanes” refers to a commercially obtainedmixture of C₆₋₉ aliphatic hydrocarbons available under the tradedesignation Isopar E®, from ExxonMobil Chemical Company. In the eventthe name of a compound herein does not conform to the structuralrepresentation thereof, the structural representation shall control. Thesynthesis of all metal complexes and the preparation of all screeningexperiments were carried out in a dry nitrogen atmosphere using dry boxtechniques. All solvents used were HPLC grade and were dried beforetheir use.

MMAO refers to modified methylalumoxane, a triisobutylaluminum modifiedmethylalumoxane available commercially from Akzo-Noble Corporation.

The preparation of catalyst (B1) is conducted as follows.

a) Preparation of(1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)methylimine

3,5-Di-t-butylsalicylaldehyde (3.00 g) is added to 10 mL ofisopropylamine. The solution rapidly turns bright yellow. After stirringat ambient temperature for 3 hours, volatiles are removed under vacuumto yield a bright yellow, crystalline solid (97 percent yield).

b) Preparation of1,2-bis-(3,5-di-t-butylphenylene)(1-N-(1-methylethyl)immino)methyl)(2-oxoyl)zirconium dibenzyl

A solution of (1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)imine (605mg, 2.2 mmol) in 5 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (500 mg, 1.1 mmol) in 50 mL toluene. The resulting darkyellow solution is stirred for 30 min. Solvent is removed under reducedpressure to yield the desired product as a reddish-brown solid.

The preparation of catalyst (B2) is conducted as follows.

a) Preparation of(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine

2-Methylcyclohexylamine (8.44 mL, 64.0 mmol) is dissolved in methanol(90 mL), and di-t-butylsalicaldehyde (10.00 g, 42.67 mmol) is added. Thereaction mixture is stirred for three hours and then cooled to −25° C.for 12 hrs. The resulting yellow solid precipitate is collected byfiltration and washed with cold methanol (2×15 mL), and then dried underreduced pressure. The yield is 11.17 g of a yellow solid. ¹H NMR isconsistent with the desired product as a mixture of isomers.

b) Preparation ofbis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dibenzyl

A solution of(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine (7.63g, 23.2 mmol) in 200 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (5.28 g, 11.6 mmol) in 600 mL toluene. The resulting darkyellow solution is stirred for 1 hour at 25° C. The solution is dilutedfurther with 680 mL toluene to give a solution having a concentration of0.00783 M.

Cocatalyst 1 A mixture of methyldi(C₁₄₋₁₈ alkyl)ammonium salts oftetrakis(pentafluorophenyl)borate (here-in-after armeenium borate),prepared by reaction of a long chain trialkylamine (Armeen™ rm M2HT,available from Akzo-Nobel, Inc.), HCl and Li[B(C₆F₅)₄], substantially asdisclosed in U.S. Pat. No. 5,919,9883, Ex. 2.

Cocatalyst 2 Mixed C₁₄₋₁₈ alkyldimethylammonium salt ofbis(tris(pentafluorophenyl)-alumane)-2-undecylimidazolide, preparedaccording to U.S. Pat. No. 6,395,671, Ex. 16.

Shuttling Agents The shuttling agents employed include diethylzinc (DEZ,SA1), di(i-butyl)zinc (SA2), di(n-hexyl)zinc (SA3), triethylaluminum(TEA, SA4), trioctylaluminum (SA5), triethylgallium (SA6),i-butylaluminum bis(dimethyl(t-butyl)siloxane) (SA7), i-butylaluminumbis(di(trimethylsilyl)amide) (SA8), n-octylaluminumdi(pyridine-2-methoxide) (SA9), bis(n-octadecyl)i-butylaluminum (SA10),i-butylaluminum bis(di(n-pentyl)amide) (SA11), n-octylaluminumbis(2,6-di-t-butylphenoxide) (SA12), n-octylaluminumdi(ethyl(1-naphthyl)amide) (SA13), ethylaluminumbis(t-butyldimethylsiloxide) (SA14), ethylaluminumdi(bis(trimethylsilyl)amide) (SA15), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide) (SA16), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide) (SA17), n-octylaluminumbis(dimethyl(t-butyl)siloxide (SA18), ethylzinc (2,6-diphenylphenoxide)(SA19), and ethylzinc (t-butoxide) (SA20).

Examples 1-4, Comparative Examples A*-C*

General High Throughput Parallel Polymerization Conditions

Polymerizations are conducted using a high throughput, parallelpolymerization reactor (PPR) available from Symyx technologies, Inc. andoperated substantially according to U.S. Pat. Nos. 6,248,540, 6,030,917,6,362,309, 6,306,658, and 6,316,663. Ethylene copolymerizations areconducted at 130° C. and 200 psi (1.4 MPa) with ethylene on demand using1.2 equivalents of cocatalyst 1 based on total catalyst used (1.1equivalents when MMAO is present). A series of polymerizations areconducted in a parallel pressure reactor (PPR) contained of 48individual reactor cells in a 6×8 array that are fitted with apre-weighed glass tube. The working volume in each reactor cell is 6000μL. Each cell is temperature and pressure controlled with stirringprovided by individual stirring paddles. The monomer gas and quench gasare plumbed directly into the PPR unit and controlled by automaticvalves. Liquid reagents are robotically added to each reactor cell bysyringes and the reservoir solvent is mixed alkanes. The order ofaddition is mixed alkanes solvent (4 ml), ethylene, 1-octene comonomer(1 ml), cocatalyst 1 or cocatalyst 1/MMAO mixture, shuttling agent, andcatalyst or catalyst mixture. When a mixture of cocatalyst 1 and MMAO ora mixture of two catalysts is used, the reagents are premixed in a smallvial immediately prior to addition to the reactor. When a reagent isomitted in an experiment, the above order of addition is otherwisemaintained. Polymerizations are conducted for approximately 1-2 minutes,until predetermined ethylene consumptions are reached. After quenchingwith CO, the reactors are cooled and the glass tubes are unloaded. Thetubes are transferred to a centrifuge/vacuum drying unit, and dried for12 hours at 60° C. The tubes containing dried polymer are weighed andthe difference between this weight and the tare weight gives the netyield of polymer. Results are contained in Table 1. In Table 1 andelsewhere in the application, comparative compounds are indicated by anasterisk (*).

Examples 1-4 demonstrate the synthesis of linear block copolymers by thepresent invention as evidenced by the formation of a very narrow MWD,essentially monomodal copolymer when DEZ is present and a bimodal, broadmolecular weight distribution product (a mixture of separately producedpolymers) in the absence of DEZ. Due to the fact that Catalyst (A1) isknown to incorporate more octene than Catalyst (B1), the differentblocks or segments of the resulting copolymers of the invention aredistinguishable based on branching or density.

TABLE 1 Cat. (A1) Cat (B1) Cocat MMAO shuttling Ex. (μmol) (μmol) (μmol)(μmol) agent (μmol) Yield (g) Mn Mw/Mn hexyls¹ A* 0.06 — 0.066 0.3 —0.1363 300502 3.32 — B* — 0.1 0.110 0.5 — 0.1581 36957 1.22 2.5 C* 0.060.1 0.176 0.8 — 0.2038 45526 5.30² 5.5 1 0.06 0.1 0.192 — DEZ (8.0)0.1974 28715 1.19 4.8 2 0.06 0.1 0.192 — DEZ (80.0) 0.1468 2161 1.1214.4 3 0.06 0.1 0.192 — TEA (8.0) 0.208 22675 1.71 4.6 4 0.06 0.1 0.192— TEA (80.0) 0.1879 3338 1.54 9.4 ¹C₆ or higher chain content per 1000carbons ²Bimodal molecular weight distribution

It may be seen the polymers produced according to the invention have arelatively narrow polydispersity (Mw/Mn) and larger block-copolymercontent (trimer, tetramer, or larger) than polymers prepared in theabsence of the shuttling agent.

Further characterizing data for the polymers of Table 1 are determinedby reference to the figures. More specifically DSC and ATREF resultsshow the following:

The DSC curve for the polymer of example 1 shows a 115.7° C. meltingpoint (Tm) with a heat of fusion of 158.1 J/g. The corresponding CRYSTAFcurve shows the tallest peak at 34.5° C. with a peak area of 52.9percent. The difference between the DSC Tm and the Tcrystaf is 81.2° C.

The DSC curve for the polymer of example 2 shows a peak with a 109.7° C.melting point (Tm) with a heat of fusion of 214.0 J/g. The correspondingCRYSTAF curve shows the tallest peak at 46.2° C. with a peak area of57.0 percent. The difference between the DSC Tm and the Tcrystaf is63.5° C.

The DSC curve for the polymer of example 3 shows a peak with a 120.7° C.melting point (Tm) with a heat of fusion of 160.1 J/g. The correspondingCRYSTAF curve shows the tallest peak at 66.1° C. with a peak area of71.8 percent. The difference between the DSC Tm and the Tcrystaf is54.6° C.

The DSC curve for the polymer of example 4 shows a peak with a 104.5° C.melting point (Tm) with a heat of fusion of 170.7 J/g. The correspondingCRYSTAF curve shows the tallest peak at 30° C. with a peak area of 18.2percent. The difference between the DSC Tm and the Tcrystaf is 74.5° C.

The DSC curve for Comparative Example A shows a 90.0° C. melting point(Tm) with a heat of fusion of 86.7 J/g. The corresponding CRYSTAF curveshows the tallest peak at 48.5° C. with a peak area of 29.4 percent.Both of these values are consistent with a resin that is low in density.The difference between the DSC Tm and the Tcrystaf is 41.8° C.

The DSC curve for Comparative Example B* shows a 129.8° C. melting point(Tm) with a heat of fusion of 237.0 J/g. The corresponding CRYSTAF curveshows the tallest peak at 82.4° C. with a peak area of 83.7 percent.Both of these values are consistent with a resin that is high indensity. The difference between the DSC Tm and the Tcrystaf is 47.4° C.

The DSC curve for Comparative Example C* shows a 125.3° C. melting point(Tm) with a heat of fusion of 143.0 J/g. The corresponding CRYSTAF curveshows the tallest peak at 81.8° C. with a peak area of 34.7 percent aswell as a lower crystalline peak at 52.4° C. The separation between thetwo peaks is consistent with the presence of a high crystalline and alow crystalline polymer. The difference between the DSC Tm and theTcrystaf is 43.5° C.

Examples 5-19, Comparative Examples D*-F*, Continuous SolutionPolymerization, Catalyst A1/B2+DEZ

Continuous solution polymerizations are carried out in a computercontrolled autoclave reactor equipped with an internal stirrer. Purifiedmixed alkanes solvent (Isopar™ E available from ExxonMobil ChemicalCompany), ethylene at 2.70 lbs/hour (1.22 kg/hour), 1-octene, andhydrogen (where used) are supplied to a 3.8 L reactor equipped with ajacket for temperature control and an internal thermocouple. The solventfeed to the reactor is measured by a mass-flow controller. A variablespeed diaphragm pump controls the solvent flow rate and pressure to thereactor. At the discharge of the pump, a side stream is taken to provideflush flows for the catalyst and cocatalyst 1 injection lines and thereactor agitator. These flows are measured by Micro-Motion mass flowmeters and controlled by control valves or by the manual adjustment ofneedle valves. The remaining solvent is combined with 1-octene,ethylene, and hydrogen (where used) and fed to the reactor. A mass flowcontroller is used to deliver hydrogen to the reactor as needed. Thetemperature of the solvent/monomer solution is controlled by use of aheat exchanger before entering the reactor. This stream enters thebottom of the reactor. The catalyst component solutions are meteredusing pumps and mass flow meters and are combined with the catalystflush solvent and introduced into the bottom of the reactor. The reactoris run liquid-full at 500 psig (3.45 MPa) with vigorous stirring.Product is removed through exit lines at the top of the reactor. Allexit lines from the reactor are steam traced and insulated.Polymerization is stopped by the addition of a small amount of waterinto the exit line along with any stabilizers or other additives andpassing the mixture through a static mixer. The product stream is thenheated by passing through a heat exchanger before devolatilization. Thepolymer product is recovered by extrusion using a devolatilizingextruder and water cooled pelletizer. Process details and results arecontained in Table 2. Selected polymer properties are provided in Table3.

TABLE 2 Process details for preparation of exemplary polymers Cat Cat A1Cat B2 DEZ Cocat Cocat Poly C₈H₁₆ Solv. T A1² Flow B2³ Flow DEZ FlowConc. Flow [C₂H₄]/ Rate⁵ Conv Ex. kg/hr kg/hr H₂ sccm¹ ° C. ppm kg/hrppm kg/hr Conc % kg/hr ppm kg/hr [DEZ]⁴ kg/hr %⁶ Solids % Eff.⁷ D* 1.6312.7 29.90 120 142.2  0.14 — — 0.19 0.32  820 0.17 536 1.81 88.8 11.295.2 E* ″  9.5 5.00 ″ — — 109 0.10 0.19 ″ 1743 0.40 485 1.47 89.9 11.3126.8 F* ″ 11.3 251.6 ″ 71.7 0.06 30.8 0.06 — — ″ 0.11 — 1.55 88.5 10.3257.7  5 ″ ″ — ″ ″ 0.14 30.8 0.13 0.17 0.43 ″ 0.26 419 1.64 89.6 11.1118.3  6 ″ ″ 4.92 ″ ″ 0.10 30.4 0.08 0.17 0.32 ″ 0.18 570 1.65 89.3 11.1172.7  7 ″ ″ 21.70 ″ ″ 0.07 30.8 0.06 0.17 0.25 ″ 0.13 718 1.60 89.210.6 244.1  8 ″ ″ 36.90 ″ ″ 0.06 ″ ″ ″ 0.10 ″ 0.12 1778 1.62 90.0 10.8261.1  9 ″ ″ 78.43 ″ ″ ″ ″ ″ ″ 0.04 ″ ″ 4596 1.63 90.2 10.8 267.9 10 ″ ″0.00 123 71.1 0.12 30.3 0.14 0.34 0.19 1743 0.08 415 1.67 90.31 11.1131.1 11 ″ ″ ″ 120 71.1 0.16 ″ 0.17 0.80 0.15 1743 0.10 249 1.68 89.5611.1 100.6 12 ″ ″ ″ 121 71.1 0.15 ″ 0.07 ″ 0.09 1743 0.07 396 1.70 90.0211.3 137.0 13 ″ ″ ″ 122 71.1 0.12 ″ 0.06 ″ 0.05 1743 0.05 653 1.69 89.6411.2 161.9 14 ″ ″ ″ 120 71.1 0.05 ″ 0.29 ″ 0.10 1743 0.10 395 1.41 89.429.3 114.1 15 2.45 ″ ″ ″ 71.1 0.14 ″ 0.17 ″ 0.14 1743 0.09 282 1.80 89.3311.3 121.3 16 ″ ″ ″ 122 71.1 0.10 ″ 0.13 ″ 0.07 1743 0.07 485 1.78 90.1111.2 159.7 17 ″ ″ ″ 121 71.1 0.10 ″ 0.14 ″ 0.08 1743 ″ 506 1.75 89.0811.0 155.6 18 0.69 ″ ″ 121 71.1 ″ ″ 0.22 ″ 0.11 1743 0.10 331 1.25 89.938.8 90.2 19 0.32 ″ ″ 122 71.1 0.06 ″ ″ ″ 0.09 1743 0.08 367 1.16 90.748.4 106.0 *Comparative, not an example of the invention ¹standardcm³/min²[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl³bis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dibenzyl ⁴molar ratio in reactor ⁵polymer production rate⁶percent ethylene conversion in reactor ⁷efficiency, kg polymer/g Mwhere g M = g Hf + g Zr

TABLE 3 Properties of exemplary polymers Heat of CRYSTAF Density Mw MnFusion T_(m) T_(c) T_(CRYSTAF) Tm − T_(CRYSTAF) Peak Area Ex. (g/cm³) I₂I₁₀ I₁₀/I₂ (g/mol) (g/mol) Mw/Mn (J/g) (° C.) (° C.) (° C.) (° C.)(percent) D* 0.8627 1.5 10.0 6.5 110,000 55,800 2.0 32 37 45 30 7 99 E*0.9378 7.0 39.0 5.6 65,000 33,300 2.0 183 124 113 79 45 95 F* 0.8895 0.912.5 13.4 137,300 9,980 13.8 90 125 111 78 47 20  5 0.8786 1.5 9.8 6.7104,600 53,200 2.0 55 120 101 48 72 60  6 0.8785 1.1 7.5 6.5 10960053300 2.1 55 115 94 44 71 63  7 0.8825 1.0 7.2 7.1 118,500 53,100 2.2 69121 103 49 72 29  8 0.8828 0.9 6.8 7.7 129,000 40,100 3.2 68 124 106 8043 13  9 0.8836 1.1 9.7 9.1 129600 28700 4.5 74 125 109 81 44 16 100.8784 1.2 7.5 6.5 113,100 58,200 1.9 54 116 92 41 75 52 11 0.8818 9.159.2 6.5 66,200 36,500 1.8 63 114 93 40 74 25 12 0.8700 2.1 13.2 6.4101,500 55,100 1.8 40 113 80 30 83 91 13 0.8718 0.7 4.4 6.5 132,10063,600 2.1 42 114 80 30 81 8 14 0.9116 2.6 15.6 6.0 81,900 43,600 1.9123 121 106 73 48 92 15 0.8719 6.0 41.6 6.9 79,900 40,100 2.0 33 114 9132 82 10 16 0.8758 0.5 3.4 7.1 148,500 74,900 2.0 43 117 96 48 69 65 170.8757 1.7 11.3 6.8 107,500 54,000 2.0 43 116 96 43 73 57 18 0.9192 4.124.9 6.1 72,000 37,900 1.9 136 120 106 70 50 94 19 0.9344 3.4 20.3 6.076,800 39,400 1.9 169 125 112 80 45 88

The resulting polymers are tested by DSC and ATREF as with previousexamples. Results are as follows:

The DSC curve for the polymer of example 5 shows a peak with a 119.6° C.melting point (Tm) with a heat of fusion of 60.0 J/g. The correspondingCRYSTAF curve shows the tallest peak at 47.6° C. with a peak area of59.5 percent. The delta between the DSC Tm and the Tcrystaf is 72.0° C.

The DSC curve for the polymer of example 6 shows a peak with a 115.2° C.melting point (Tm) with a heat of fusion of 60.4 J/g. The correspondingCRYSTAF curve shows the tallest peak at 44.2° C. with a peak area of62.7 percent. The delta between the DSC Tm and the Tcrystaf is 71.0° C.

The DSC curve for the polymer of example 7 shows a peak with a 121.3° C.melting point with a heat of fusion of 69.1 J/g. The correspondingCRYSTAF curve shows the tallest peak at 49.2° C. with a peak area of29.4 percent. The delta between the DSC Tm and the Tcrystaf is 72.1° C.

The DSC curve for the polymer of example 8 shows a peak with a 123.5° C.melting point (Tm) with a heat of fusion of 67.9 J/g. The correspondingCRYSTAF curve shows the tallest peak at 80.1° C. with a peak area of12.7 percent. The delta between the DSC Tm and the Tcrystaf is 43.4° C.

The DSC curve for the polymer of example 9 shows a peak with a 124.6° C.melting point (Tm) with a heat of fusion of 73.5 J/g. The correspondingCRYSTAF curve shows the tallest peak at 80.8° C. with a peak area of16.0 percent. The delta between the DSC Tm and the Tcrystaf is 43.8° C.

The DSC curve for the polymer of example 10 shows a peak with a 115.6°C. melting point (Tm) with a heat of fusion of 60.7 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 40.9° C. with apeak area of 52.4 percent. The delta between the DSC Tm and the Tcrystafis 74.7° C.

The DSC curve for the polymer of example 11 shows a peak with a 113.6°C. melting point (Tm) with a heat of fusion of 70.4 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 39.6° C. with apeak area of 25.2 percent. The delta between the DSC Tm and the Tcrystafis 74.1° C.

The DSC curve for the polymer of example 12 shows a peak with a 113.2°C. melting point (Tm) with a heat of fusion of 48.9 J/g. Thecorresponding CRYSTAF curve shows no peak equal to or above 30° C.(Tcrystaf for purposes of further calculation is therefore set at 30°C.). The delta between the DSC Tm and the Tcrystaf is 83.2° C.

The DSC curve for the polymer of example 13 shows a peak with a 114.4°C. melting point (Tm) with a heat of fusion of 49.4 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 33.8° C. with apeak area of 7.7 percent. The delta between the DSC Tm and the Tcrystafis 84.4° C.

The DSC for the polymer of example 14 shows a peak with a 120.8° C.melting point (Tm) with a heat of fusion of 127.9 J/g. The correspondingCRYSTAF curve shows the tallest peak at 72.9° C. with a peak area of92.2 percent. The delta between the DSC Tm and the Tcrystaf is 47.9° C.

The DSC curve for the polymer of example 15 shows a peak with a 114.3°C. melting point (Tm) with a heat of fusion of 36.2 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 32.3° C. with apeak area of 9.8 percent. The delta between the DSC Tm and the Tcrystafis 82.0° C.

The DSC curve for the polymer of example 16 shows a peak with a 116.6°C. melting point (Tm) with a heat of fusion of 44.9 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 48.0° C. with apeak area of 65.0 percent. The delta between the DSC Tm and the Tcrystafis 68.6° C.

The DSC curve for the polymer of example 17 shows a peak with a 116.0°C. melting point (Tm) with a heat of fusion of 47.0 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 43.1° C. with apeak area of 56.8 percent. The delta between the DSC Tm and the Tcrystafis 72.9° C.

The DSC curve for the polymer of example 18 shows a peak with a 120.5°C. melting point (Tm) with a heat of fusion of 141.8 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 70.0° C. with apeak area of 94.0 percent. The delta between the DSC Tm and the Tcrystafis 50.5° C.

The DSC curve for the polymer of example 19 shows a peak with a 124.8°C. melting point (Tm) with a heat of fusion of 174.8 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 79.9° C. with apeak area of 87.9 percent. The delta between the DSC Tm and the Tcrystafis 45.0° C.

The DSC curve for the polymer of Comparative Example D* shows a peakwith a 37.3° C. melting point (Tm) with a heat of fusion of 31.6 J/g.The corresponding CRYSTAF curve shows no peak equal to and above 30° C.Both of these values are consistent with a resin that is low in density.The delta between the DSC Tm and the Tcrystaf is 7.3° C.

The DSC curve for the polymer of Comparative Example E* shows a peakwith a 124.0° C. melting point (Tm) with a heat of fusion of 179.3 J/g.The corresponding CRYSTAF curve shows the tallest peak at 79.3° C. witha peak area of 94.6 percent. Both of these values are consistent with aresin that is high in density. The delta between the DSC Tm and theTcrystaf is 44.6° C.

The DSC curve for the polymer of Comparative Example F* shows a peakwith a 124.8° C. melting point (Tm) with a heat of fusion of 90.4 J/g.The corresponding CRYSTAF curve shows the tallest peak at 77.6° C. witha peak area of 19.5 percent. The separation between the two peaks isconsistent with the presence of both a high crystalline and a lowcrystalline polymer. The delta between the DSC Tm and the Tcrystaf is47.2° C.

Physical Property Testing

Polymer samples are evaluated for physical properties such as hightemperature resistance properties, as evidenced by TMA temperaturetesting, pellet blocking strength, high temperature recovery, hightemperature compression set and storage modulus ratio, G′(25°C.)/G′(100° C.). Several commercially available polymers are included inthe tests: Comparative Example G* is a substantially linearethylene/1-octene copolymer (AFFINITY®, available from The Dow ChemicalCompany), Comparative Example H* is an elastomeric, substantially linearethylene/1-octene copolymer (AFFINITY®EG8100, available from The DowChemical Company), Comparative Example I* is a substantially linearethylene/1-octene copolymer (AFFINITY®PL 1840, available from The DowChemical Company), Comparative Example J* is a hydrogenatedstyrene/butadiene/styrene triblock copolymer (KRATON™ G1652, availablefrom KRATON Polymers), Comparative Example K* is a thermoplasticvulcanizate (TPV, a polyolefin blend containing dispersed therein acrosslinked elastomer). Results are presented in Table 4.

TABLE 4 High Temperature Mechanical Properties TMA-1 mm Pellet Blocking300% Strain penetration Strength G′(25° C.)/ Recovery (80° C.)Compression Set Ex. (° C.) lb/ft² (kPa) G′(100° C.) (percent) (70° C.)(percent) D* 51 — 9 Failed — E* 130 — 18 — — F* 70 141 (6.8)  9 Failed100   5 104 0 (0)  6 81 49  6 110 — 5 — 52  7 113 — 4 84 43  8 111 — 4Failed 41  9 97 — 4 — 66 10 108 — 5 81 55 11 100 — 8 — 68 12 88 — 8 — 7913 95 — 6 84 71 14 125 — 7 — — 15 96 — 5 — 58 16 113 — 4 — 42 17 108 0(0)  4 82 47 18 125 — 10 — — 19 133 — 9 — — G* 75 463 (22.2) 89 Failed100  H* 70 213 (10.2) 29 Failed 100  I* 111 — 11 — — J* 107 — 5 Failed100  K* 152 — 3 — 40

In Table 4, Comparative Example F* (which is a physical blend of the twopolymers resulting from simultaneous polymerizations using catalyst A1and B1) has a 1 mm penetration temperature of about 70° C., whileExamples 5-9 have a 1 mm penetration temperature of 100° C. or greater.Further, examples 10-19 all have a 1 mm penetration temperature ofgreater than 85° C., with most having 1 mm TMA temperature of greaterthan 90° C. or even greater than 100° C. This shows that the novelpolymers have better dimensional stability at higher temperaturescompared to a physical blend. Comparative Example J* (a commercial SEBS)has a good 1 mm TMA temperature of about 107° C., but it has very poor(high temperature 70° C.) compression set of about 100 percent and italso failed to recover (sample broke) during a high temperature (80° C.)300 percent strain recovery. Thus the exemplified polymers have a uniquecombination of properties unavailable even in some commerciallyavailable, high performance thermoplastic elastomers.

Similarly, Table 4 shows a low (good) storage modulus ratio, G′(25°C.)/G′(100° C.), for the inventive polymers of 6 or less, whereas aphysical blend (Comparative Example F*) has a storage modulus ratio of 9and a random ethylene/octene copolymer (Comparative Example G*) ofsimilar density has a storage modulus ratio an order of magnitudegreater (89). It is desirable that the storage modulus ratio of apolymer be as close to 1 as possible. Such polymers will be relativelyunaffected by temperature, and fabricated articles made from suchpolymers can be usefully employed over a broad temperature range. Thisfeature of low storage modulus ratio and temperature independence isparticularly useful in elastomer applications such as in pressuresensitive adhesive formulations.

The data in Table 4 also demonstrate that the polymers of the inventionpossess improved pellet blocking strength. In particular, Example 5 hasa pellet blocking strength of 0 MPa, meaning it is free flowing underthe conditions tested, compared to Comparative Examples F* and G* whichshow considerable blocking. Blocking strength is important since bulkshipment of polymers having large blocking strengths can result inproduct clumping or sticking together upon storage or shipping,resulting in poor handling properties.

High temperature (70° C.) compression set for the inventive polymers isgenerally good, meaning generally less than about 80 percent, preferablyless than about 70 percent and especially less than about 60 percent. Incontrast, Comparative Examples F*, G*, H* and J* all have a 70° C.compression set of 100 percent (the maximum possible value, indicatingno recovery). Good high temperature compression set (low numericalvalues) is especially needed for applications such as gaskets, windowprofiles, o-rings, and the like.

TABLE 5 Ambient Temperature Mechanical Properties Tensile 100% 300%Retractive Stress Abrasion: Notched Strain Strain Stress Com- Relax-Flex Tensile Tensile Elongation Tensile Elongation Volume Tear RecoveryRecovery at 150% pression ation Modulus Modulus Strength at Break¹Strength at Break Loss Strength 21° C. 21° C. Strain Set 21° C. at 50%Ex. (MPa) (MPa) (MPa)¹ (%) (MPa) (%) (mm³) (mJ) (percent) (percent)(kPa) (Percent) Strain² D* 12 5 — — 10 1074 — — 91 83 760 — — E* 895 589— 31 1029 — — — — — — — F* 57 46 — — 12 824 93 339 78 65 400 42 —  5 3024 14 951 16 1116 48 — 87 74 790 14 33  6 33 29 — — 14 938 — — — 75 86113 —  7 44 37 15 846 14 854 39 — 82 73 810 20 —  8 41 35 13 785 14 81045 461 82 74 760 22 —  9 43 38 — — 12 823 — — — — — 25 — 10 23 23 — — 14902 — — 86 75 860 12 — 11 30 26 — — 16 1090 — 976 89 66 510 14 30 12 2017 12 961 13 931 — 1247  91 75 700 17 — 13 16 14 — — 13 814 — 691 91 — —21 — 14 212 160 — — 29 857 — — — — — — — 15 18 14 12 1127  10 1573 —2074  89 83 770 14 — 16 23 20 — — 12 968 — — 88 83 1040  13 — 17 20 18 —— 13 1252 — 1274  13 83 920  4 — 18 323 239 — — 30 808 — — — — — — — 19706 483 — — 36 871 — — — — — — — G* 15 15 — — 17 1000 — 746 86 53 110 2750 H* 16 15 — — 15 829 — 569 87 60 380 23 — I* 210 147 — — 29 697 — — —— — — — J* — — — — 32 609 — — 93 96 1900  25 — K* — — — — — — — — — — —30 — ¹Tested at 51 cm/minute ²measured at 38° C. for 12 hours

Table 5 shows results for mechanical properties for the new polymers aswell as for various comparison polymers at ambient temperatures. It maybe seen that the inventive polymers have very good abrasion resistancewhen tested according to ISO 4649, generally showing a volume loss ofless than about 90 mm³, preferably less than about 80 mm³, andespecially less than about 50 mm³. In this test, higher numbers indicatehigher volume loss and consequently lower abrasion resistance.

Tear strength as measured by tensile notched tear strength of theinventive polymers is generally 1000 mJ or higher, as shown in Table 5.Tear strength for the inventive polymers can be as high as 3000 mJ, oreven as high as 5000 mJ. Comparative polymers generally have tearstrengths no higher than 750 mJ.

Table 5 also shows that the polymers of the invention have betterretractive stress at 150 percent strain (demonstrated by higherretractive stress values) than some of the comparative samples.Comparative Examples F*, G* and H* have retractive stress value at 150percent strain of 400 kPa or less, while the inventive polymers haveretractive stress values at 150 percent strain of 500 kPa (Ex. 11) to ashigh as about 1100 kPa (Ex. 17). Polymers having higher than 150 percentretractive stress values would be quite useful for elastic applications,such as elastic fibers and fabrics, especially nonwoven fabrics. Otherapplications include diaper, hygiene, and medical garment waistbandapplications, such as tabs and elastic bands.

Table 5 also shows that stress relaxation (at 50 percent strain) is alsoimproved (less) for the inventive polymers as compared to, for example,Comparative Example G*. Lower stress relaxation means that the polymerretains its force better in applications such as diapers and othergarments where retention of elastic properties over long time periods atbody temperatures is desired.

Optical Testing

TABLE 6 Polymer Optical Properties Ex. Internal Haze (percent) Clarity(percent) 45° Gloss (percent) F* 84 22 49 G* 5 73 56  5 13 72 60  6 3369 53  7 28 57 59  8 20 65 62  9 61 38 49 10 15 73 67 11 13 69 67 12 875 72 13 7 74 69 14 59 15 62 15 11 74 66 16 39 70 65 17 29 73 66 18 6122 60 19 74 11 52 G* 5 73 56 H* 12 76 59 I* 20 75 59

The optical properties reported in Table 6 are based on compressionmolded films substantially lacking in orientation. Optical properties ofthe polymers may be varied over wide ranges, due to variation incrystallite size, resulting from variation in the quantity of chainshuttling agent employed in the polymerization.

Extractions of Multi-Block Copolymers

Extraction studies of the polymers of examples 5, 7 and ComparativeExample E* are conducted. In the experiments, the polymer sample isweighed into a glass fritted extraction thimble and fitted into aKumagawa type extractor. The extractor with sample is purged withnitrogen, and a 500 mL round bottom flask is charged with 350 mL ofdiethyl ether. The flask is then fitted to the extractor. The ether isheated while being stirred. Time is noted when the ether begins tocondense into the thimble, and the extraction is allowed to proceedunder nitrogen for 24 hours. At this time, heating is stopped and thesolution is allowed to cool. Any ether remaining in the extractor isreturned to the flask. The ether in the flask is evaporated under vacuumat ambient temperature, and the resulting solids are purged dry withnitrogen. Any residue is transferred to a weighed bottle usingsuccessive washes of hexane. The combined hexane washes are thenevaporated with another nitrogen purge, and the residue dried undervacuum overnight at 40° C. Any remaining ether in the extractor ispurged dry with nitrogen.

A second clean round bottom flask charged with 350 mL of hexane is thenconnected to the extractor. The hexane is heated to reflux with stirringand maintained at reflux for 24 hours after hexane is first noticedcondensing into the thimble. Heating is then stopped and the flask isallowed to cool. Any hexane remaining in the extractor is transferredback to the flask. The hexane is removed by evaporation under vacuum atambient temperature, and any residue remaining in the flask istransferred to a weighed bottle using successive hexane washes. Thehexane in the flask is evaporated by a nitrogen purge, and the residueis vacuum dried overnight at 40° C.

The polymer sample remaining in the thimble after the extractions istransferred from the thimble to a weighed bottle and vacuum driedovernight at 40° C. Results are contained in Table 7.

TABLE 7 ether ether C₈ hexane hexane C₈ residue wt. soluble soluble molesoluble soluble mole C₈ mole Sample (g) (g) (percent) percent¹ (g)(percent) percent¹ percent¹ Comp. 1.097 0.063 5.69 12.2 0.245 22.35 13.66.5 F* Ex. 5 1.006 0.041 4.08 — 0.040 3.98 14.2 11.6 Ex. 7 1.092 0.0171.59 13.3 0.012 1.10 11.7 9.9 ¹Determined by ¹³C NMR

Additional Polymer Examples 19 A-F, Continuous Solution Polymerization,Catalyst A1/B2+DEZ

Continuous solution polymerizations are carried out in a computercontrolled well-mixed reactor. Purified mixed alkanes solvent (Isopar™ Eavailable from ExxonMobil Chemical Company), ethylene, 1-octene, andhydrogen (where used) are combined and fed to a 27 gallon reactor. Thefeeds to the reactor are measured by mass-flow controllers. Thetemperature of the feed stream is controlled by use of a glycol cooledheat exchanger before entering the reactor. The catalyst componentsolutions are metered using pumps and mass flow meters. The reactor isrun liquid-full at approximately 550 psig pressure. Upon exiting thereactor, water and additive are injected in the polymer solution. Thewater hydrolyzes the catalysts, and terminates the polymerizationreactions. The post reactor solution is then heated in preparation for atwo-stage devolatization. The solvent and unreacted monomers are removedduring the devolatization process. The polymer melt is pumped to a diefor underwater pellet cutting.

Process details and results are contained in Table 8. Selected polymerproperties are provided in Table 9 and Table 9A.

TABLE 8 Polymerization Conditions Cat Cat Cat Cat A1² A1 B2³ B2 DEZ DEZC₂H₄ C₈H₁₆ Solv. H₂ T Conc. Flow Conc. Flow Conc Flow Ex. lb/hr lb/hrlb/hr sccm¹ ° C. ppm lb/hr ppm lb/hr wt % lb/hr 19a 55.29 32.03 323.03101 120 600 0.25 200 0.42 3.0 0.70 19b 53.95 28.96 325.3 577 120 6000.25 200 0.55 3.0 0.24 19c 55.53 30.97 324.37 550 120 600 0.216 2000.609 3.0 0.69 19d 54.83 30.58 326.33 60 120 600 0.22 200 0.63 3.0 1.3919e 54.95 31.73 326.75 251 120 600 0.21 200 0.61 3.0 1.04 19f 50.4334.80 330.33 124 120 600 0.20 200 0.60 3.0 0.74 19g 50.25 33.08 325.61188 120 600 0.19 200 0.59 3.0 0.54 19h 50.15 34.87 318.17 58 120 6000.21 200 0.66 3.0 0.70 19i 55.02 34.02 323.59 53 120 600 0.44 200 0.743.0 1.72 19k 7.46 9.04 50.6 47 120 150 0.22 76.7 0.36 0.5 0.19 [Zn]⁴Cocat 1 Cocat 1 Cocat 2 Cocat 2 in Poly Conc. Flow Conc. Flow polymerRate⁵ Conv⁶ Polymer Ex. ppm lb/hr ppm lb/hr ppm lb/hr wt % wt % Eff⁷ 19a4500 0.65 525 0.33 248 83.94 88.0 17.28 297 19b 4500 0.63 525 0.11  9080.72 88.1 17.2 295 19c 4500 0.61 525 0.33 246 84.13 88.9 17.16 293 19d4500 0.66 525 0.66 491 82.56 88.1 17.07 280 19e 4500 0.64 525 0.49 36884.11 88.4 17.43 288 19f 4500 0.52 525 0.35 257 85.31 87.5 17.09 319 19g4500 0.51 525 0.16 194 83.72 87.5 17.34 333 19h 4500 0.52 525 0.70 25983.21 88.0 17.46 312 19i 4500 0.70 525 1.65 600 86.63 88.0 17.6 275 19k— — — — — — — — — ¹standard cm³/min²[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl³bis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dimethyl ⁴ppm in final product calculated by mass balance⁵polymer production rate ⁶weight percent ethylene conversion in reactor⁷efficiency, kg polymer/g M where g M = g Hf + g Z

TABLE 9 Polymer Physical properties Heat CRYSTAF of Tm − Peak PolymerDensity Mw Mn Fusion Tm Tc TCRYSTAF TCRYSTAF Area Ex. No. (g/cc) I2 I10I10/I2 (g/mol) (g/mol) Mw/Mn (J/g) (° C.) (° C.) (° C.) (° C.) (wt %)19g 0.8649 0.9 6.4 7.1 135000 64800 2.1 26 120 92 30 90 90 19h 0.86541.0 7.0 7.1 131600 66900 2.0 26 118 88 — — —

TABLE 9A Average Block Index For exemplary polymers¹ Example Zn/C₂ ²Average BI Polymer F 0 0 Polymer 8 0.56 0.59 Polymer 19a 1.3 0.62Polymer 5 2.4 0.52 Polymer 19b 0.56 0.54 Polymer 19h 3.15 0.59¹Additional information regarding the calculation of the block indicesfor various polymers is disclosed in U.S. Patent Application Ser. No.     (insert when known), entitled “Ethylene/α-Olefin BlockInterpolymers”, filed on Mar. 15, 2006, in the name of Colin L. P. Shan,Lonnie Hazlitt, et. al. and assigned to Dow Global Technologies Inc.,the disclose of which is incorporated by reference herein in itsentirety. ²Zn/C₂ * 1000 = (Zn feed flow * Zn concentration/1000000/Mw ofZn)/(Total Ethylene feed flow * (1 − fractional ethylene conversionrate)/Mw of Ethylene) * 1000. Please note that “Zn” in “Zn/C₂ * 1000”refers to the amount of zinc in diethyl zinc (“DEZ”) used in thepolymerization process, and “C2” refers to the amount of ethylene usedin the polymerization process.

Polymer Examples 20-25 and Comparative Examples A**-E**

Various multi-block copolymers having differing degrees of soft segmentto hard segment weight ratios are compared to physical blends ofmetallocene polymers and Ziegler Natta produced polymers at similar softto hard segment ratios to show how the blocked structure of the backboneperforms differently from a physical blend of the same type of segments.Various physical properties, including compression set, abrasionresistance, can be improved. Maintaining a low Shore hardness value isespecially useful in forming gaskets and closures. The addition of acarboxylic acid copolymer and/or amide slip agents enhances some ofthese performance properties.

TABLE 10 Soft Segment/ Overall Hard Zinc in Density, Segment PolymerPolymer Example Melt Index, g/10 min g/cm³ Ratio ppm 20 1 0.877 70/30250 21 1 0.877 70/30 188 22 1 0.877 70/30 88 23 5 0.877 70/30 500 24 10.866 85/15 250 25 1 0.893 50/50 >500 A** 39.2 14.2 70/30 20.9 B** 71.817.7 5050 34.7 C** 13.4 18.2 NA 21.4 D** 11.0 11.7 NA 23.0 E** 51.0 31.2NA 44.9 NA = Not applicable **= Comparative Example A = ENGAGE ®* 8842(1 melt index, 0.857 g/cm3, I10/I2 of about 8.3, metallocene)/DOWLEX ®*2042 (7.7 melt index, 0.93 g/cm3, Ziegler Natta) B = ENGAGE ®*/DOWLEX ®*2042 Blend C = AFFINITY ®* 8100 (1 melt index, 0.87 g/cm3, Mw/Mn about2, metallocene) D = AFFINITY ®* 8200 (5 melt index, 0.87 g/cm3,metallocene) E = AFFINITY ®* PF 1140 (1.6 melt index, 0.8965 g/cm3,metallocene) *Trademark of The Dow Chemical Co. All polymers areethylene/1-octene copolymers

TABLE 11 Flexural Tensile Trouser Hardness Hardness Modulus ElastomerTear Comp. set Comp. set shore A shore D Abrasion Density Example (Mpa)(Mpa) (N/mm) (23° C. 72 hrs) (70° C. 24 hrs) 15 sec 15 sec DIN (mm3)(g/cc) 20 24.3 19.3 28.0 14.4 39.1 77.3 22.7 51.2 0.8785 21 24.6 19.428.3 14.0 35.6 76.4 22.8 48.3 0.8786 22 21.2 18.5 24.3 17.6 44.4 74.921.8 54.1 0.8775 23 18.7 12.1 27.4 16.9 51.3 72.7 19.2 98.5 0.8768 248.4 14.8 19.1 18.5 59.1 56.5 12.7 151.0 0.8653 25 57.8 24.0 40.4 15.033.7 89.5 32.5 31.3 0.8915 A** 39.2 14.2 20.9 32.8 76.6 72.9 21.3 213.80.879 B** 71.8 17.7 34.7 26.9 60.1 89.0 32.3 102.6 0.8919 C** 13.4 18.221.4 39.2 98.1 73.1 21.1 107.5 0.873 D** 11.0 11.7 23.0 39.2 88.9 70.718.9 208.8 0.8719 E** 51.0 31.2 44.9 30.4 78.8 91.6 37.8 18.8 0.8955

Examples of Polymer Blend Compositions

Polymer blend compositions comprising the ethylene/α-olefininterpolymers of Examples 26-28 and at least one other polymer wereprepared, evaluated and tested for properties. Ethylene/α-olefininterpolymers of Examples 26-28 were made according to proceduressimilar to thoese described herein. The melt index and overall densityfor these ethylene/α-olefin interpolymers is provided below:

Example No. Oveall Density I₂ Polymer Example 26 0.877 1 Polymer Example27 0.878 5 Polymer Example 28 0.878 15

The following methods were used to determine the properties of theblends:

100% Modulus, Modulus at 100% elongation, with crosshead velocity of 500mm/min, MPa measured in mega Pascals, according to ISO 37 Type 1,(1994). UTS, MPa Ultimate tensile strength, with crosshead velocity of500 mm/min, measured in mega Pascals, according to ISO 37 Type 1 (1994).Ult. Elong. % Ultimate elongation percent, with crosshead velocity of500 mm/min, according to ISO 37 Type 1 (1994). Tear Strength, Tearstrength, with crosshead velocity of 500 mm/min, measured kN/m in kN/m,according to ISO 34 Method B (1994). Hardness Shore A durometer hardnessmeasured at 15 seconds and at room temperature (23° C.), according toISO 868 (1985). Compression Compression set, at 125° C. for 70 hours,measured as a Set, % percentage, according to ISO 815 Type A, pliedsample (1991). Oil Swell, wt. % Oil swell, at 125° C. for 70 hours usingIRM903 oil, measured in percent by weight, according to ISO 1817 (1999).Gel Content, % Percent gel content, or crosslinked EPDM, measured bysoaking ~1 g of chopped (≦1 mm) pellets in ~100 g of cyclohexane at 23°C. for 48 hours, and weighing the dried residue, then subtracting theweight of the components soluble in cyclohexane, other than rubber, suchas extender oil, antioxidant, light Stabilizer, etc. Shear ViscosityApparent viscosity was measured at 230° C. with a capillary die 15 × 1mm, according to ASTM D-3835 (1996), at an apparent shear rate of 500sec⁻¹.

Tables 12 and 13 provides various ingredients used in the blends andproperties of the blend compositions.

TABLE 12 Polymer properties for exemplary polymer blends CompressionCompression Avg % Set for 22 Set for 22 COF (on COF (on Density - ELON-Hours - 23 C. Hours - 70 C. Metal) - Metal) - 40 Hours Hardness GATIONBlend Composition (73 F.) (158 F.) dynamic static @ B-3833 (Shore A) (%)Comparative Resins EVA 25.8 ND 0.63 0.96 0.9312 80.2 619 Septon ® 8006 8.2 29.3% ND ND ND ND ND Kraton G 1562 12.7 98.4% ND ND ND ND NDNexprene ® 9055 17.6 26.4% ND ND ND ND ND Engage ® 8770 23.9 ND ND ND0.8850 86.0 ND Engage ® 8100 20.1 84.7% ND ND 0.8790 62.0 ND Affinity ®SM 1300 ND ND ND ND ND ND ND Ethylene/α-olefin interpolymer containingND ND ND ND ND ND ND polymer blend compositions 83.33% Polymer Example28/14.67% Polymer 30.5 59.8% 2.00 2.00 0.8786 76.8 1280  Example26/2.00% Kemamide E Ultra 27.93% Polymer Example 26/70.70% LLDPE 43.4 ND0.29 0.46 0.9057 85.2 900 2517/2.00% Kemamide E Ultra 98.00% PolymerExample 28/2.00% Kemamide 28.2 64.2% 2.00 2.00 0.8766 76.6 249 E Ultra89.00% Polymer Example 28/09.00% Elvax ® 29.4 63.9% 2.00 2.00 0.882969.2 1126  650Q/2.00% Kemamide E Ultra 89.00% Polymer Example 28/09.00%Elvax ® 28.6 61.0% 2.00 2.00 0.8827 72.6 1087  750/2.00% Kemamide EUltra 83.30% Polymer Example 28/14.70% Versify ™ 28.5 67.3% 2.00 2.000.8768 75.4 ND DE 3300.01/2.00% Kemamide E Ultra 68.60% Polymer Example28/29.40% Versify ™ 36.6 72.9% 2.00 2.00 0.8755 71.8 996 DE3300.01/2.00% Kemamide E Ultra 83.30% Polymer Example 28/14.70%Versify ™ 28.4 63.4% 1.87 2.00 0.8798 76.2 495 DE 3300.01/2.00% KemamideE Ultra 68.60% Polymer Example 28/29.40% Versify ™ 30.5 65.4% 1.59 1.850.8817 83.2 366 DE 3300.01/2.00% Kemamide E Ultra 29.40% Polymer Example28/68.60% LDPE 722/ 39.6 72.6% 0.29 0.41 0.9066 84.4 698 2.00% KemamideE Ultra 49.00% Polymer Example 28/49.00% LDPE 722/ 36.6 68.0% 0.56 0.730.8982 80.8 788 2.00% Kemamide E Ultra 68.60% Polymer Example 28/29.40%LDPE 722/ 34.8 65.0% 1.19 1.51 0.8899 80.0 661 2.00% Kemamide E Ultra55.76% Polymer Example 27/42.24% LLDPE 2517/ 37.0 61.5% 0.91 1.30 0.894779.0 973 2.00% Kemamide E Ultra 68.60% Polymer Example 28/29.40%Septon ® 4055/ ND 51.5% 2.00 2.00 0.8864 70.6 828 2.00% Kemamide E Ultra75.65% Polymer Example 28/13.35% 27.3 65.8% 2.00 2.00 0.8849 73.4 522Versify ™ 3000.01/09.00% Elvax ® 650Q/2.00% Kemamide E Ultra 75.65%Polymer Example 28/13.35% 25.1 63.9% 2.00 2.00 0.8841 75.4 590Versify ™ 3000.01/09.00% Elvax ® 750/2.00% Kemamide E Ultra 43.80%Polymer Example 26/29.20% Septon ® 4055/ 27.9 ND 2.00 2.00 0.8860 70.4731 25.00% Affinity ® GA 1950/2.00% Kemamide E Ultra 43.80% PolymerExample 26/29.20% Septon ® 8006/ 27.5 ND 2.00 2.00 0.8894 67.4 ND 25.00%Affinity ® GA 1950/2.00% Kemamide E Ultra 68.60% Polymer Example28/29.40% DMDA-8007/ 46.8 ND 0.77 1.02 0.8997 82.6 333 2.00% Kemamide EUltra 68.60% Polymer Example 28/29.40% hPP H700-12/ 37.0 78.2% 1.17 1.740.8846 79.2 158 2.00% Kemamide E Ultra 88.20% Polymer Example 28/09.80%hPP H700-12/ 28.1 62.3% 1.99 2.00 0.8800 71.6 787 2.00% Kemamide E Ultra71.52% Polymer Example 26/26.48% DMDA-8965/ 42.7 ND 0.87 1.33 0.896681.6 885 2.00% Kemamide E Ultra 75.65% Polymer Example 28/13.35% 25.1 ND1.90 1.97 0.8834 75.8 518 Versify ™ 3000.01/2.00% Kemamide E Ultra48.00% Polymer Example 28/48.00% LDPE 722/ ND ND 1.63 1.82 ND ND ND4.00% MB-50-002 98.00% AFFINITY ® SM 1300G/2.00% Kemamide E 21.4 ND 0.580.94 0.9050 77.4 835 Ultra 98.00% Elvax ® 650Q/2.00% Kemamide E Ultra25.8 ND 0.63 0.96 0.9312 80.2 619 68.60% Polymer Example 26/29.40%Septon ® 4055/ ND ND 2.00 2.00 0.8865 72.2 689 2.00% Kemamide E Ultra/49.80% Polymer Example 26/33.20% Septon ® 4055/ ND ND 2.00 2.00 0.887071.4 696 15.00% Affinity ® GA 1950/2.00% Kemamide E Ultra/ ND = Notdetermined

TABLE 13 Polymer properties for exemplary polymer blends Avg Off Avg AvgAvg Adj Avg Adj Yield 100% 300% Avg Avg Avg Yield Yield Gage Gage LoadMod- Mod- Thickness Ultimate Width Strain Strength Blend CompositionLen1 (In) Len2 (In) (Lb) ulus ulus (In) (Psi) (In) (%) (Psi) ComparativeResins EVA 1.00 2.50 17.18 876 296 0.109 1377 0.25 8.56 628 Septon ®8006 Kraton G 1562 Nexprene ® 9055 Engage ® 8770 Engage ® 8100Affinity ® SM 1300 Ethylene/α-olefin interpolymer containing polymerblend compositions 83.33% Polymer Example 28/14.67% Polymer 1.00 2.506.60 1236  529 0.121 569 0.25 8.06 218 Example 26/2.00% Kemamide E Ultra27.93% Polymer Example 26/70.70% LLDPE 1.00 2.50 22.44  877 282 0.1111830 0.25 6.72 805 2517/2.00% Kemamide E Ultra 98.00% Polymer Example28/2.00% 1.00 2.50 6.42 1226  523 0.117 433 0.25 8.07 219 Kemamide EUltra 89.00% Polymer Example 28/09.00% Elvax ® 1.00 2.50 6.16 387 1450.111 497 0.25 7.93 221 650Q/2.00% Kemamide E Ultra 89.00% PolymerExample 28/09.00% Elvax ® 1.00 2.50 5.94 394 145 0.107 488 0.25 6.90 221750/2.00% Kemamide E Ultra 83.30% Polymer Example 28/14.70% ND ND ND NDND ND ND ND ND ND Versify ™ DE 3300.01/2.00% Kemamide E Ultra 68.60%Polymer Example 28/29.40% 1.00 2.50 6.18 1181  441 0.112 332 0.25 6.99220 Versify ™ DE 3300.01/2.00% Kemamide E Ultra 83.30% Polymer Example28/14.70% 1.00 2.50 7.30 1471  635 0.111 401 0.25 8.03 262 Versify ™ DE3300.01/2.00% Kemamide E Ultra 68.60% Polymer Example 28/29.40% 1.002.50 9.02 1805  766 0.11  451 0.25 8.48 328 Versify ™ DE 3300.01/2.00%Kemamide E Ultra 29.40% Polymer Example 28/68.60% LDPE 1.00 2.50 21.88 3813  1351  0.109 918 0.25 7.04 802 722/2.00% Kemamide E Ultra 49.00%Polymer Example 28/49.00% LDPE 1.00 2.50 16.00  2866  1036  0.111 8080.25 7.16 574 722/2.00% Kemamide E Ultra 68.60% Polymer Example28/29.40% LDPE 1.00 2.50 10.40  1991  762 0.111 499 0.25 7.41 374722/2.00% Kemamide E Ultra 55.76% Polymer Example 27/42.24% LLDPE 1.002.50 13.74  619 206 0.114 1218 0.25 7.60 481 2517/2.00% Kemamide E Ultra68.60% Polymer Example 28/29.40% 1.00 2.50 4.70 318 137 0.118 1251 0.256.02 159 Septon ® 4055/2.00% Kemamide E Ultra 75.65% Polymer Example28/13.35% 1.00 2.50 8.02 485 168 0.108 384 0.25 8.20 296 Versify ™3000.01/09.00% Elvax ® 650Q/ 2.00% Kemamide E Ultra 75.65% PolymerExample 28/13.35% 1.00 2.50 7.84 471 169 0.113 440 0.25 7.15 278Versify ™ 3000.01/09.00% Elvax ® 750/ 2.00% Kemamide E Ultra 43.80%Polymer Example 26/29.20% 1.00 2.50 5.02 302 137 0.121 1364 0.25 5.89167 Septon ® 4055/25.00% Affinity ® GA 1950/ 2.00% Kemamide E Ultra43.80% Polymer Example 26/29.20% ND ND ND ND ND ND ND ND ND ND Septon ®8006/25.00% Affinity ® GA 1950/ 2.00% Kemamide E Ultra 68.60% PolymerExample 28/29.40% DMDA- 1.00 2.50 15.08  682 223 0.11  567 0.25 7.02 5518007/2.00% Kemamide E Ultra 68.60% Polymer Example 28/29.40% hPP 1.002.50 10.98  567  0 0.113 460 0.25 7.76 389 H700-12/2.00% Kemamide EUltra 88.20% Polymer Example 28/09.80% hPP 1.00 2.50 5.76 407 151 0.109398 0.25 5.77 212 H700-12/2.00% Kemamide E Ultra 71.52% Polymer Example26/26.48% DMDA- 1.00 2.50 14.44  676 257 0.12  1721 0.25 7.36 4828965/2.00% Kemamide E Ultra 75.65% Polymer Example 28/13.35% 1.00 2.507.54 472 169 0.11  463 0.25 7.03 275 Versify ™ 3000.01/2.00% Kemamide EUltra 48.00% Polymer Example 28/48.00% LDPE ND ND ND ND ND ND ND ND NDND 722/4.00% MB-50-002 98.00% AFFINITY ® SM 1300G/2.00% 1.00 2.50 18.22 939 295 0.107 1566 0.25 7.65 682 Kemamide E Ultra 98.00% Elvax ®650Q/2.00% Kemamide E 1.00 2.50 17.18  876 296 0.109 1377 0.25 8.56 628Ultra 68.60% Polymer Example 26/29.40% 1.00 2.50 5.52 337 162 0.124 16150.25 7.69 178 Septon ® 4055/2.00% Kemamide E Ultra 49.80% PolymerExample 26/33.20% 1.00 2.50 4.72 316 149 0.12  1435 0.25 6.13 158Septon ® 4055/15.00% Affinity ® GA 1950/ 2.00% Kemamide E Ultra ND = Notdetermined

As seen from the data provided in Tables 12 and 13, various physicalproperties, including compression set, abrasion resistance, wereimproved, while maintaining a low Shore hardness value in the polymerblends comprising at least one ethylene/α-olefin interpolymer. Suchproperties are especially useful in forming the gaskets and closuresprovided herein.

In some embodiments, the addition of a carboxylic acid copolymer and/oramide slip agents enhances some of these performance properties.

Another improvement is a more puncture resistant surface. Using amicroscope and a metal probe, the puncture resistance of the surface ona series of closure liners is observed. The surface of closure liners(contained Surly™ 1702) do not break until the probe penetrates about 4mils into the liner. Conversely, the surface of closure liners withoutany ethylene/carboxylic acid in the formulation break almost immediatelyupon penetration.

The surface of liners containing the ethylene/carboxylic acid copolymeralways respond differently to the polarized light, implying that thesurface is more crystalline and/or more oriented; both of which wouldresult in a more puncture resistant surface. The addition of thesecomponents improves the “stringing and scuffing” resistance of the linerbecause of enhanced slip performance and a more puncture resistant skinlayer.

While the invention has been described with respect to a limited numberof embodiments, the specific features of one embodiment should not beattributed to other embodiments of the invention. No single embodimentis representative of all aspects of the invention. In some embodiments,the compositions or methods may include numerous compounds or steps notmentioned herein. In other embodiments, the compositions or methods donot include, or are substantially free of, any compounds or steps notenumerated herein. Variations and modifications from the describedembodiments exist. Finally, any number disclosed herein should beconstrued to mean approximate, regardless of whether the word “about” or“approximately” is used in describing the number. The appended claimsintend to cover all those modifications and variations as falling withinthe scope of the invention.

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 1. A polymerblend composition comprising: (A) at least one ethylene/α-olefininterpolymer and (B) at least one other polymer, wherein theethylene/α-olefin interpolymer is a block interpolymer and: (a) has aM_(w)/M_(n) from about 1.7 to about 3.5, at least one melting point,T_(m), in degrees Celsius, and a density, d, in grams/cubic centimeter,wherein the numerical values of T_(m) and d correspond to therelationship:T _(m)>−2002.9+4538.5(d)−2422.2(d)², or (b) has a M_(w)/M_(n) from about1.7 to about 3.5, and is characterized by a heat of fusion, ΔH in J/g,and a delta quantity, ΔT, in degrees Celsius, defined as the temperaturedifference between the tallest DSC peak and the tallest CRYSTAF peak,wherein the numerical values of ΔT and ΔH have the followingrelationships:ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,ΔT≧48° C. for ΔH greater than 130 J/g, wherein the CRYSTAF peak isdetermined using at least 5 percent of the cumulative polymer, and ifless than 5 percent of the polymer has an identifiable CRYSTAF peak,then the CRYSTAF temperature is 30° C.; or (c) is characterized by anelastic recovery, Re, in percent at 300 percent strain and 1 cyclemeasured with a compression-molded film of the ethylene/α-olefininterpolymer, and has a density, d, in grams/cubic centimeter, whereinthe numerical values of Re and d satisfy the following relationship whenethylene/α-olefin interpolymer is substantially free of a cross-linkedphase:Re>1481−1629(d); or (d) has a molecular fraction which elutes between40° C. and 130° C. when fractionated using TREF, characterized in thatthe fraction has a molar comonomer content of at least 5 percent higherthan that of a comparable random ethylene interpolymer fraction elutingbetween the same temperatures, wherein said comparable random ethyleneinterpolymer has the same comonomer(s) and has a melt index, density,and molar comonomer content (based on the whole polymer) within 10percent of that of the ethylene/α-olefin interpolymer; or (e) has astorage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C.,G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in therange of about 1:1 to about 9:1; or (f) at least one molecular fractionwhich elutes between 40° C. and 130° C. when fractionated using TREF,characterized in that the fraction has a block index of at least 0.5 andup to about 1 and a molecular weight distribution, Mw/Mn, greater thanabout 1.3; or (g) an average block index greater than zero and up toabout 1.0 and a molecular weight distribution, Mw/Mn, greater than about1.3.
 2. The composition of claim 1, wherein the other polymer isselected from a second ethylene α-olefin interpolymer, an elastomer, apolyolefin, a polar polymer, and an ethylene/carboxylic acidinterpolymer or ionomer thereof, the second ethylene/α-olefininterpolymer is different than the first ethylene/α-olefin interpolymerand the second ethylene/α-olefin interpolymer: (a) has a M_(w)/M_(n)from about 1.7 to about 3.5, at least one melting point, T_(m), indegrees Celsius, and a density, d, in grams/cubic centimeter, whereinthe numerical values of T_(m) and d correspond to the relationship:T _(m)>−2002.9+4538.5(d)−2422.2(d)², or (b) has a M_(w)/M_(n) from about1.7 to about 3.5, and is characterized by a heat of fusion, ΔH in J/g,and a delta quantity, ΔT, in degrees Celsius, defined as the temperaturedifference between the tallest DSC peak and the tallest CRYSTAF peak,wherein the numerical values of ΔT and ΔH have the followingrelationships:ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,ΔT≧48° C. for AH greater than 130 J/g, wherein the CRYSTAF peak isdetermined using at least 5 percent of the cumulative polymer, and ifless than 5 percent of the polymer has an identifiable CRYSTAF peak,then the CRYSTAF temperature is 30° C.; or (c) is characterized by anelastic recovery, Re, in percent at 300 percent strain and 1 cyclemeasured with a compression-molded film of the ethylene/α-olefininterpolymer, and has a density, d, in grams/cubic centimeter, whereinthe numerical values of Re and d satisfy the following relationship whenethylene/α-olefin interpolymer is substantially free of a cross-linkedphase:Re>1481−1629(d); or (d) has a molecular fraction which elutes between40° C. and 130° C. when fractionated using TREF, characterized in thatthe fraction has a molar comonomer content of at least 5 percent higherthan that of a comparable random ethylene interpolymer fraction elutingbetween the same temperatures, wherein said comparable random ethyleneinterpolymer has the same comonomer(s) and has a melt index, density,and molar comonomer content (based on the whole polymer) within 10percent of that of the ethylene/α-olefin interpolymer; or (e) has astorage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C.,G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in therange of about 1:1 to about 9:1; or (f) at least one molecular fractionwhich elutes between 40° C. and 130° C. when fractionated using TREF,characterized in that the fraction has a block index of at least 0.5 andup to about 1 and a molecular weight distribution, M_(w)/M_(n), greaterthan about 1.3; or (g) an average block index greater than zero and upto about 1.0 and a molecular weight distribution, M_(w)/M_(n), greaterthan about 1.3.
 3. The composition of claim 1, wherein the firstethylene/α-olefin interpolymer is present in an amount ranging fromabout 9% to 99.5% and the second ethylene/α-olefin interpolymer ispresent in an amount ranging from about 9% to 99.5% by weight of thetotal weight of the composition.
 4. The composition of claim 1, whereinthe other polymer is an elastomer selected from a thermoplasticvulcanizate, styrenic block copolymer, neoprene, functionalizedelastomers, polybutadiene rubber, butyl rubber or a combination thereof.5. The composition of claim 1, wherein the other polymer is a polyolefinselected from LDPE, LLDPE, HDPE, EVA, EAA, EMA, ionomers thereof,metallocene LLDPE, impact grade propylene polymer, random gradepropylene polymer, polypropylene and a combination thereof.
 6. Thecomposition of claim 1, wherein the other polymer is a polar polymerselected from nylon, polyamide, ethylene vinyl acetate, polyvinylchloride, acrylonitrile butadiene/styrene (ABS) copolymers, aromaticpolycarbonate, ethylene/carboxylic acid copolymers, polyacrylic and acombination thereof.
 7. The composition of claim 1, wherein the otherpolymer is an olefin/carboxylic acid interpolymer selected fromethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer,ethylene-itaconic acid copolymer, ethylene-methyl hydrogen maleatecopolymer, ethylene-maleic acid copolymer, ethylene-acrylic acidcopolymer, ethylene-methacrylate copolymer, ethylene-methacrylicacid-ethacrylate copolymer, ethylene-itaconic acid-methacrylatecopolymer, ethylene-itaconic acid-methacrylate copolymer,ethylene-methyl hydrogen maleate-ethyl acrylate copolymer,ethylene-methacrylic acid-vinyl acetate copolymer, ethylene-acrylic acidcopolymer, ethylene-acrylic acid-vinyl alcohol copolymer,ethylene-acrylic acid-carbon monoxide copolymer,ethylene-propylene-acrylic acid copolymer, ethylene-methacrylicacid-acrylonitrile copolymer, ethylene-fumaric acid-vinyl methyl ethercopolymer, ethylene-vinyl chloride-acrylic acid copolymer,ethylene-vinylidene chloride-acrylic acid copolymer, ethylene-vinylidenechloride-acrylic acid copolymer, ethylene-vinyl fluoride-methacrylicacid copolymes, ethylene-chlorotrifluoroethlyene-methacrylic acidcopolymer, or a combination thereof.
 8. The composition of claim 1,further comprising an additive selected from a slip agent, ananti-blocking agent, a plasticizer, an antioxidant, a UV stabilizer, acolorant, a filler, a lubricant, an antifogging agent, a flow aid, aacoupling agent, a cross-linking agent, a nucleating agent, asurfactant, a solvent, a flame retardant, an antistatic agent, anextender, an odor absorber, a barrier resin and a combination thereof.9. The composition of claim 8, wherein the slip agent ispolymethylsiloxane, erucamide, oleamide or a combination thereof. 10.The composition of claim 8, wherein the odor absorber is calciumcarbonate, activated charcoal or a combination thereof.
 11. Thecomposition of claim 8, wherein the barrier resin is ethylene vinylalcohol (EVOH) copolymer or polyvinylidene chloride (PVDC).
 12. Thecomposition of claim 8, wherein the extender is a mineral oil,polybutene, siloxane, or a combination thereof.
 13. A gasket comprisingthe composition of claims
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